Large Swap file

Model Name:    MacBook Pro
Model Identifier:    MacBookPro6,2
Processor Name:    Intel Core i5
Processor Speed:    2.53 GHz
Number Of Processors:    1
Total Number Of Cores:    2
L2 Cache (per core):    256 KB
L3 Cache:    3 MB
Memory:    8 GB
Processor Interconnect Speed:    4.8 GT/s
Running the latest version of Parallels and Windows 7 64 bit.
Using the Activity monitor I find that I always have a large swap file (even when parallels is not running), a huge amount of inactive memory and a very small free memory. It slows down my system. Any suggestions?

First, upgrade your system to 10.6.7 or 10.6.8. Second, large swap files don't necessarily mean a thing. You might see the following:
About OS X Memory Management and Usage
Reading system memory usage in Activity Monitor
Memory Management in Mac OS X
Performance Guidelines- Memory Management in Mac OS X
A detailed look at memory usage in OS X
Understanding top output in the Terminal
The amount of available RAM for applications is the sum of Free RAM and Inactive RAM. This will change as applications are opened and closed or change from active to inactive status. The Swap figure represents an estimate of the total amount of swap space required for VM if used, but does not necessarily indicate the actual size of the existing swap file. If you are really in need of more RAM that would be indicated by how frequently the system uses VM. If you open the Terminal and run the top command at the prompt you will find information reported on Pageins () and Pageouts (). Pageouts () is the important figure. If the value in the parentheses is 0 (zero) then OS X is not making instantaneous use of VM which means you have adequate physical RAM for the system with the applications you have loaded. If the figure in parentheses is running positive and your hard drive is constantly being used (thrashing) then you need more physical RAM.
Adding RAM only makes it possible to run more programs concurrently. It doesn't speed up the computer nor make games run faster. What it can do is prevent the system from having to use disk-based VM when it runs out of RAM because you are trying to run too many applications concurrently or using applications that are extremely RAM dependent. It will improve the performance of applications that run mostly in RAM or when loading programs.
Bear in mind you are running Parallels and a VM concurrently with some other OS X applications. Too many concurrent applications will result in using too much memory and increasing swapping.

Similar Messages

Large swap file (900MB), but no pageouts

My MacBook Air 13" with 4GB of RAM accumulates a large swap file over time, but pageouts are 0 (page ins: 1.1million). Anyone know why? Is it possible to see which process/application currently have pages stored in the swap file?

Sorry to dig this old thread up, but I am seeing an identical behavior to the original poster, and I just wanted to say—you did an excellent job of explaining how page ins can be very large with no pageouts, but I don't think this explains the real mystery, which is that there is a large amount of swap space, and a large amount the system says is used, but there are no page outs. You have not explained how a swap file gan grow in usage with no page outs, and if I understand things correctly, this should not be possible.
I'm having the same issue on my new MacBook Pro with Retina display. I have 16GB of RAM and for the most part I don't use more than 4-6GB of that—I bought it for the occasional times I need to do a lot of VM testing, but I haven't needed to do that yet. I consistently see my swap usage grow to be as large as 2-3GB with a total size for all the swapfiles in /var/vm being 3-4GB.
I don't need the space, and the system isn't slow or anything. I just want to know how this is possible. I have been using Mac OS X for 10 years now, and working on linux servers for 5 years or so. I've never seen swap usage be more than 0KB when there are no page outs.
I've attached some screenshots of what I am seeing:
Screen capture from Activity Monitor.
Screen capture from Terminal executing 'du -hsc /var/vm/swapfile*' to tally the total size of the swapfiles.
I should note that it tends to take a day or two of use to start to see this, in a series of sleep cycles here and there. I put my laptop to sleep at night as well as to and from work, etc. It probably sleeps/wakes 5-7 times a day in all. I tend to notice that the usage creeps up, starting atound 50 MB, then I will notice it being a few hundred some time later. It really makes me wonder if this has to do with some kind of discrete vs. dedicated graphics switching or something, perhaps a very low level operation that is somehow avoiding getting counted by the system's resource tracking facilities. I have no idea, but I would love it if there were someone out there who could explain it or point me in the right direction.
Thanks for your time.

Generate large swap file (Use qtparted to generate partition

Desire to generate a 30GB swap file in Linux using the full capacity of a hard drive as swap.
Can this be done with the arch0.5 install CD?
I assume I must skip the auto feature to do so. I do not know if the CD program will allow skipping the program install steps and just install lilo.
Perhaps someone has done a similar thing?

i3839;
Thanks for the comments.
The desired entry is not to hdd but to ram such that all operations take place in ram...no hdd used...no CD orDVD used (except tp start the ram install).
While in ram, all video is improved when uncompressed video is entered (.vob for instance) and the result is higher quality and better resolution.
The basic question is in reference to arch install CD and whether it can be utilized to generate a HDD with just swap (one or more partitions) .
My experience with the arch CD indicates it doesn't like the install to skip any steps. Perhaps I can try a partition install and then abort the rest. I think it will allow three separate swap (type 82) partitions: at the least one of 2GB. Perhaps it is programmed however, to require a root and a boot as well as a swap.
I suggest you read the previous post which describes the install to ram...called 'toram' in knoppix. This doesn't use the hdd, just the dvd reader. It can however utilize a hdd file entered in a dvd install....tohd.. and add the cheat code ...toram..
The end result is a ram only OS which can utilize USB hotplug devices for entry and storage, turning them off when not in use.
The present system here has 2.5GB of ram but it is not able to accept the DVD of 2GB when attempting ..toram. The same ...toram..cheat code is available for the CD version which operates well in ram (only 680MB). The use of swap to augment ram is recommended.
Dvd versions have close to 5GB of programs in compressed form in the 2.1GB DVD media.
I hope this post helps describe the need for the swap a little better.

How to diagnose large swap usage

Hi,
We have a java application that is connecting to our oracle 10g database. When the application is not connected the swap file usage on the solaris box is about 1GB. But soon as we startup the java application and connect it to oracle the swap usage jumps to a massive 16GB (and stays like that until with shutdown the application - it does not really grow any more)
The application actually looks fine and works without problems - expect the database is hammering the machine with the swap file. can anyone give me some hints at where I can look on the database to try and diagnose what is acutally causing this large swap file creation - in an attempt what is this application doing? At the moment I am confused as to what could actually cause this.
thx.
S.

Hi, I'd use the iosnoop, iotop, rwsnoop and rwtop commands available in dtrace package (eg. http://users.tpg.com.au/adsln4yb/DTrace/dtracevstruss.html). It can tell a lot about i/o operations, also according to swap. But it only applies to the OS, I can't help you with the Oracle...

VAR and Swap Files - Taking up 3 gigs of space!

My 60 gig HD has been getting close to its size limit so I ran DiskSweeper to see if there were some unneeded files etc. that I could throw away. I discovered that the VAR folder was using 1.95 gigs and in the VM folder, the swap files were taking up about 1 gig...
I guess these are essential system files and can’t be deleted or reduced in size, or can they?
Thanks in advance!

To clear the swap file(s) restart your computer. I've never had more than two swap files, but then I have enough RAM for what I do. If your system keeps creating large swap files then it is a sign you need more RAM. If you can't get more, you'll need to limit the number of RAM hungry programs you have running at the same time. Because of the things that get dynamically created as you work, such as swap files and temp files, you should have a minimum of 10% of your drive free, and 15 would be safer. If I were you I would make sure I always had 10GBs free. You might look into getting an external drive, and move some of your files over to it. For instance, you can move your iTunes music library to another drive--I've done that because my startup drive is also a "mere" 60GBs.
Francine
Schwieder

RAM large swap and paging after open large video file

Hi I'm using an i7 MBP with 4GB RAM. I have an issue, after watching a movie on the mac (file size about 4-5 GB) with vlc player, I found my RAM Swap jumped from 512MB to 3GB, and an substantial increased in paging (page in around 800k, page out around 100k).
After closing the player, my MBP become super slow and I have to wait for several minutes for it to stabilize itself, and still with a little retard here and there.
Could anyone enlighten me on this problem?
Thank you.

About OS X Memory Management and Usage
Reading system memory usage in Activity Monitor
Memory Management in Mac OS X
Performance Guidelines- Memory Management in Mac OS X
A detailed look at memory usage in OS X
Understanding top output in the Terminal
The amount of available RAM for applications is the sum of Free RAM and Inactive RAM. This will change as applications are opened and closed or change from active to inactive status. The Swap figure represents an estimate of the total amount of swap space required for VM if used, but does not necessarily indicate the actual size of the existing swap file. If you are really in need of more RAM that would be indicated by how frequently the system uses VM. If you open the Terminal and run the top command at the prompt you will find information reported on Pageins () and Pageouts (). Pageouts () is the important figure. If the value in the parentheses is 0 (zero) then OS X is not making instantaneous use of VM which means you have adequate physical RAM for the system with the applications you have loaded. If the figure in parentheses is running positive and your hard drive is constantly being used (thrashing) then you need more physical RAM.

Changing swap file location on tray-loader iMacs

This is not a question, but something I discovered that makes my old tray-loader iMac (the oldest iMac models) run Mac OS X much better.
As you may know, these oldest iMacs have an 8GB size limit on the boot volume. The largest stock drive on these iMacs was 6GB. That means if your upgraded hard drive is larger than 8GB, it must be partition so that the first partition is under 8GB (7.78GB on my iMac), and it must be the boot partition where the OS is installed (whether it's Mac OS X or 9).
In my case, I have a roomy 120GB hard drive (I believe the useable limit on these iMacs is 128GB). The first partition is just under 8GB, the second partition is the rest of the space, about 104GB. I have used every trick out there to move files (such as the iTunes music folder and most of my user/documents files) off to the second partition, to make free space on the boot partition as large as possible. So I have 3.5GB free on my 8GB boot partition. This is about 40% of the volume's total space so it seems pretty good, until you realize that most recent Macs have much more than the TOTAL 8GB I have, as free space on the boot volume. Mac OS X was just not designed to work well with small boot volumes...
Mac OS X uses the free space on the boot volume for its virtual memory "swap file." Considering these old iMacs max out at 512MB of RAM, virtual memory is being used quite a bit. But since space on the boot volume is very limited, low RAM and lack of free space can lead to performance issues. Here's what I observed. When I initially started up my iMac, I had about 3.5GB of free space. Over time, as I used more and more apps, that free space would diminish until I had only about 600MB remaining (as reported by a Finder window). At the same time, I noticed performance getting bogged down and more "chugging" sounds coming from the hard-working hard drive.
I've known about changing location of the swap file, but never tried it until recently. During the Mac OS X boot process, the Mac sets the location of the swap file. By default, the swap file resides on the boot volume (I believe most other Unix-based systems use a dedicated "swap partition" for the swap file). Since most recent Macs have large drives set up as one partition (and there is plenty of free space), and since many users have upgraded their RAM (and virtual memory is not as critical), swap file location is usually not an issue, and there is certainly no need to change the swap file location. However, on my iMac with an 8GB limit on the boot volume and 512MB of RAM, it made a noticeable difference.
I found one set of procedures on the web that was much better than the others I found for changing the location of the swap file.
http://www.math.columbia.edu/~bayer/OSX/swapfile/
On this page, there are two choices for Panther users. I used the one that works for both Panther and Tiger, because it appeared to me to be more straightforward. The author intentionally keeps the instructions somewhat technical to discourage users who are not technically inclined. I don't consider myself to be too "geeky," but I can follow instructions and type a few commands in Terminal.
After I changed the swap file location to a large mostly empty volume, I noticed much better performance when I have many large apps open at the same time. Performance no longer degrades over time, and the free space on my boot volume remains a constant 3.6GB.
The reason for this post is to share this information. Some users of these old iMacs may be noticing the same issues I had. This is a possible solution. However, if everything is OK with your set up, there is no reason to change the swap file location. If you try it, be sure to take the usual data backup precautions.
If anyone else has experience with changing swap file location, please post your comments here.

Problem has been solved:
background.setCapability(Background.ALLOW_IMAGE_WRITE);Thanks everybody for reading this :)

High swap file utilization - 11g on windows 2003 x64

Hi,
I'm running database 11.1.0.6 patch set 10 on
Windows Server 2003 x64 standard
HP DL380 dual quad core + 8GB RAM
2 x 72GB 15K SAS mirror for OS
6 x 72GB 15k SAS RAID-5 for data + logs (i know ideally logs need to move to a RAID-1 set etc)
dedicated mode
database is about 10GB (main set of tables about 1GB)
SGA + PGA 4GB (auto memory management)
server has been set to network application mode such that less mem is allocated to the system cache etc.
Large Page support has been enabled (not confirmed if this is working, any ideas how to?)
Looking at the page faults and page out perf mon stats it looks too high/ too much given the arrangement above. The majority of the page faults are coming from the Oracle.exe process. But I cannot explain why specially if Large Page is setup then the SGA etc should be locked in to RAM as I understand.
side note I was seeing similar behaviour on the older 10.2.0.1 DB that had same mem config for the same set of data.
Any ideas people?
Thanks

JA,
On the server, open Task Manager and then select the Processes tab. Make certain that it is configured to show the Page Faults column and click on the entry for the Oracle instance so that it is highlighted. Then, open a command prompt and start SQL*Plus with the /NOLOG command line parameter. Make note of the current value of Page Faults and then connect to the database instance using SQL*Plus using the SYS user account (or some other account). You will probably find that the Page Faults value jumped by about 302 as a result of the login, and the value just might jump again when you disconnect from the database. Keep in mind that each session connecting to an Oracle instance running on Windows will require at least 1MB of memory immediately on connection as an additional thread is created (assuming shared server is not used). If each memory page were 4KB in size (as is the standard in Windows), there would likely be at least 256 (1MB / 4KB) page faults for each login, and possibly the same amount per disconnect. With this in mind, I am not so certain that 500 page faults per second is a high value for a Oracle process running on Windows if users/applications are constantly connecting and disconnecting from the Oracle database instance.
To determine if there is a performance problem caused by memory utilization, what you may want to do is take a look at the PF Usage value on the Performance tab of Task Manager. This is NOT the page file usage, regardless of the warnings that appear in Enterprise Manager - this is total memory allocation including RAM and swap file usage. There is an interesting thread where I discovered the actual meaning of PF Usage here:
http://groups.google.com/group/comp.databases.oracle.server/browse_thread/thread/b62c4d761cace2a6
If the PF Usage is considerably less than the amount of the RAM in the server (8GB RAM -> PF near 7GB is OK), you will likely be OK, as long as you do not attempt to move multi-gigabyte files around - doing so could cause short term memory starvation issues for Oracle. You might want to verify that the File and Printer Sharing option of the network card is set to "Maximize throughput for network applications" so that Windows will limit the memory used for file caching.
Charles Hooper
IT Manager/Oracle DBA
K&M Machine-Fabricating, Inc.

Performance Question : Swap File on SSD

In the past I've stored my swap file on a non-system disk. Now, however, my system disk is an SSD and the competition between system swaps and Photoshop swaps should be reduced if not eliminated. At least, that's what I think. I have other physical hard drives, but I'm wondering if specifying one of them for the swap file buys anything over using the SSD.
Also, what the heck does the Camera Raw cache do to increase performance? This is all over the 'net and nobody explains why but they say it will improve performance of Photoshop and Lightroom. How do you calculate the best size for the cache?
Thanks
Steve

On the issue of killing the flash drive; at the risk of being redundant, allow me to quote myself:
So, what is the current consensus on the feasibility/advisability of using flash memory for swap? I've read about the limited write cycles of flash being an argument against using it for swap. But recent reading indicates to me that the limited write cycles problem applies mostly to older, smaller-capacity flash memory. Some come right out and say that, for larger-capacity flash memory, the life of the device is likely to exceed the amount of time your current computer will be useful (I think I've seen estimates in the range of 3-4 years life--minimum--for newer, higher-capacity flash memory).
Now that we've established that the life of the flash memory is not a significant issue in this discussion, we may move on to a consideration of why I am considering NOT buying RAM. I won't quote myself on that, but suffice to say that I already have pen drives and other flash memory laying around that could be easily pressed into service for such a project. Any discussion concerning issues I've not already addressed regarding RAM vs flash memory for the task at hand?
James

Cut large audio file by duration

ok so what i am trying to do is take a large audio file, over 6 hours, and cut it down into many 10-15min files. i know i could manually just cut out what i dont want then save as a new mp3 a lot of times, but is there a way to set audition to do this automatically? i cant seem to find a way.

Now that you've placed the markers, can't you just swap the audio file in the multitrack project and reuse the same markers?
If that's no good, I used Audacity (a free program) to do this recently : http://audacity.sourceforge.net/
load up your file,
create a text file in the simple format
seconds <tab> marker name, e.g. for 10 minute files:
0 marker 1
600 marker 2
1200 marker 3
1800 marker 4
Then in audacity go project > import labels, File > export multiple.
The issue you might have is using mp3's in audacity. If you do want to use it, there's a solution here:
http://audacity.sourceforge.net/help/faq?s=install&i=lame-mp3
or you could convert to wave before cutting the files up (but that would be a big old file, and I'm not sure how well it would be handled)

Tiger swap file space

I was told this by someone at Other World Computing.
Tiger needs around 3-4GBs for installing and usually recommended to reserve 1-2GBs for the swap file space it uses during operations. The general rule of thumb for a drive is to not fill it more than 85-90% or you may experience drive slow down.
So this means that I should not let my ibook go down below 2GB's of free space. I am down to 5.5GB at this time. Downloading music has been addicting, and its a shame I did not spedn the extra $100 at the beginnign and ordered the ibook with the 60GB drive.
John

You wrote: "I keep on getting different answers. Other world computing tells me 3GB free is adaquate, but Dr. Smoke says 5GB. Who is right?"It's a controversial issue: there's no hard and fast number because it depends upon the load your placing on your Mac, how much RAM you have, and how much free disk space you have. However, I stand behind my 5 GB minimum assertion as follows:
1. If you read "Mac OS X System Requirements" it states you need:"At least 3.0 GB of available space on your hard drive; 4GB of disk space if you install XCode 2 developer tools."Therefore, to perform an Archive and Install of just the OS, you need at least 3 GB of free disk space. You certainly don't want to get to the point where you can't perform an Archive and Install of the OS due to insufficient free disk space.
2. You also need some VM swap file space: regardless of how much RAM you have, there's always at least one swap file in /private/var/vm, though it may not be large or even used if you have considerable free RAM. Based on tests I've done with a variety of Mac configurations, 2 GB seems to be a safe general margin allowance for swap files. As noted in my "Problems from insufficient RAM and free hard disk space" FAQ (have you read it?), too little swap space combined with too little RAM can lead to trashing as well as a whole host of other problems.
Add those up, and you get 5GB as an absolute minimum as a margin of safety. More free space is better, and in some cases, far more is required for a margin of safety, e.g. reserving enough free space in case one uses FileVault needs to turn it off.
Believe me or don't believe me. You asked, I answered, and can back up what I stated, as noted above.
Good luck!
Dr. Smoke
Author: Troubleshooting Mac® OS X
Note: The information provided in the link(s) above is freely available. However, because I own The X Lab™, a commercial Web site to which some of these links point, the Apple Discussions Terms of Use require I include the following disclosure statement with this post:
I may receive some form of compensation, financial or otherwise, from my recommendation or link.

Paging to Swap File

I'm on 9i R2 Patch 7 on a Microsoft Windows Server 2003.
I have constantly heard & read that allocating to much RAM to the SGA can cause paging to the swap file to disk but I have yet to read or anyone to explain how!
Can anyone please educate me how allocating a large SGA (RAM) could cause severe paging to the swap file to disk?

No I went through oracle documention and metalink support they even suggested me this Initally I was little cautious But things are smooth only drawback of this is you can not increase memory for other component you can just increase for db_block_buffer which is only one of the component SGA. if you want to monitor paging the you can do with Administrative tool .> performance monitor of windows 2003.

Swap files shortly after startup

Hello everyone
I have a MacBook 13" late 2008, 250g HD, 4g RAM
I have an unusual problem - within minutes (literally 2 or 3) after starting up the machine and opening my stock apps (Firefox, Thunderbird, Word and iCal), my system spawns 2 or more swap files (128 or 256 megs), despite there being more than 2g RAM still free. I find this unusual as it doesn't make sense to use virtual memory on my hard drive in preference to available RAM.
The reson that it is actually an issue for me is that Word (Office 11, vers 14.1.4) then becomes unusuable when swap files are present. It can take 1 minute (timed) between clicking on a Word file and it opening in Word. Closing can take up to 30 seconds. There are no lags when no swap files are present, but the presence of swap files requires a restart if I need to use Word, and using Word after the restart until the swap files are spawned.
All software (system and 3rd party) are current. I have looked in the Console logs but can't find any mention of virtual memory/swap files being spawned.
Any ideas? After several months, the preferred option is a large hammer into the laptop. It is usable in short bursts only if I have to use Word (and I do have to use Word to be compatible with my contractors etc)
Any ideas would be appreciated. Zeroing the drive is the absolute last option, and I have installed Lion and the combo updates a number of times, ditto Office 2011. Has anyone else seen this very strange behaviour?

EJW Tas wrote:
Interesting result from Activity Monitor is that Spotlight (mds) is using 100m of real memory but 2gigs of VM - I suspect that Spotlight is responsible for the extra swapfiles, perhaps as a result of a corruped index file?
That is suspicious.
The structure of Spotlight indexes was changed in Lion; you may have noticed it re-indexed everything when you upgraded. It actually created a whole new index on every volume, internal and external. There doesn't seem to be a major problem, but we do see occasions where the index gets corrupted, slowing down other indexing. This is especially noticeable when the OSX drive is being indexed, and Time Machine is doing a backup, which also needs indexing. The backup sometimes slows to a crawl, or even a virtual hang, until the OSX volume is done/fixed/excluded. I wonder if you may have a similar situation here, but affecting the data for some of your apps instead.
Do you have any other disks connected? If so, exclude them from indexing temporarily, via System Preferences > Spotlight > Privacy. See what happens after a Restart.
If not, or if that doesn't change, do the same with your internal HD.
That may provide an actual clue!

Arbitrary waveform generation from large text file

Hello,
I'm trying to use a PXI 6733 card hooked up to a BNC 2110 in a PXI 1031-DC chassis to output arbitrary waveforms at a sample rate of 100kS/s. The types of waveforms I want to generate are generally going to be sine waves of frequencies less than 10 kHz, but they need to be very high quality signals, hence the high sample rate. Eventually, we would like to go up to as high as 200 kS/s, but for right now we just want to get it to work at the lower rate.
Someone in the department has already created for me large text files > 1GB with (9) columns of numbers representing the output voltages for the channels(there will be 6 channels outputting sine waves, 3 other channels with a periodic DC voltage. The reason for the large file is that we want a continuous signal for around 30 minutes to allow for equipment testing and configuration while the signals are being generated.
I'm supposed to use this file to generate the output voltages on the 6733 card, but I keep getting numerous errors and I've been unable to get something that works. The code, as written, currently generates an error code 200290 immediately after the buffered data is output from the card. Nothing ever seems to get enqued or dequed, and although I've read the Labview help on buffers, I'm still very confused about their operation so I'm not even sure if the buffer is working properly. I was hoping some of you could look at my code, and give me some suggestions(or sample code too!) for the best way to achieve this goal.
Thanks a lot,
Chris(new Labview user)

Chris:
For context, I've pasted in the "explain error" output from LabVIEW to refer to while we work on this. More after the code...
Error -200290 occurred at an unidentified location
Possible reason(s):
The generation has stopped to prevent the regeneration of old samples. Your application was unable to write samples to the background buffer fast enough to prevent old samples from being regenerated.
To avoid this error, you can do any of the following:
1. Increase the size of the background buffer by configuring the buffer.
2. Increase the number of samples you write each time you invoke a write operation.
3. Write samples more often.
4. Reduce the sample rate.
5. Change the data transfer mechanism from interrupts to DMA if your device supports DMA.
6. Reduce the number of applications your computer is executing concurrently.
In addition, if you do not need to write every sample that is generated, you can configure the regeneration mode to allow regeneration, and then use the Position and Offset attributes to write the desired samples.
By default, the analog output on the device does what is called regeneration. Basically, if we're outputting a repeating waveform, we can simply fill the buffer once and the DAQ device will reuse the samples, reducing load on the system. What appears to be happening is that the VI can't read samples out from the file fast enough to keep up with the DAQ card. The DAQ card is set to NOT allow regeneration, so once it empties the buffer, it stops the task since there aren't any new samples available yet.
If we go through the options, we have a few things we can try:
1. Increase background buffer size.
I don't think this is the best option. Our issue is with filling the buffer, and this requires more advanced configuration.
2. Increase the number of samples written.
This may be a better option. If we increase how many samples we commit to the buffer, we can increase the minimum time between writes in the consumer loop.
3. Write samples more often.
This probably isn't as feasible. If anything, you should probably have a short "Wait" function in the consumer loop where the DAQmx write is occurring, just to regulate loop timing and give the CPU some breathing space.
4. Reduce the sample rate.
Definitely not a feasible option for your application, so we'll just skip that one.
5. Use DMA instead of interrupts.
I'm 99.99999999% sure you're already using DMA, so we'll skip this one also.
6. Reduce the number of concurrent apps on the PC.
This is to make sure that the CPU time required to maintain good loop rates isn't being taken by, say, an antivirus scanner or something. Generally, if you don't have anything major running other than LabVIEW, you should be fine.
I think our best bet is to increase the "Samples to Write" quantity (to increase the minimum loop period), and possibly to delay the DAQmx Start Task and consumer loop until the producer loop has had a chance to build the queue up a little. That should reduce the chance that the DAQmx task will empty the system buffer and ensure that we can prime the queue with a large quantity of samples. The consumer loop will wait for elements to become available in the queue, so I have a feeling that the file read may be what is slowing the program down. Once the queue empties, we'll see the DAQmx error surface again. The only real solution is to load the file to memory farther ahead of time.
Hope that helps!
Caleb Harris
National Instruments | Mechanical Engineer | http://www.ni.com/support

Problems viewing large tif files in preview

i'm having trouble viewing large tif files in preview. the tif files are on a cdrom - when i click on the file to open it, it opens only the first 250 pages of the file. the file has approximately 3,000 pages. how can i get preview to open the rest of the pages?
thanks for any suggestions.
mac mini Mac OS X (10.4.6)

no trick - i didn't create the cdrom but it only has 3 tif files with approximately 3000 pages each, not 3000 large tif files. plus several smaller pdf files, but those aren't giving me any problems.
i don't know whether they're compressed, but i still can't get more than the first 250 pages to open, even after copying the file to my desktop. if anyone has any other ideas, i'd much appreciate it.
mac mini Mac OS X (10.4.6)

Large Swap file

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