Cas latency setting

why when I set my memory timings cas latency to 2.5 and it says in the bios that cas latency is set to 2.5 does cpu-z report it being set to 2?

Quote
Originally posted by DOS
If you set any performance setting other than Slow the memory timings are set for you. If you want to overclock to 3G set the ram voltage to max 2.8, set the performance mode to Slow (bad term - is should be 'Normal'), set the DRAM clock to 333 (this will run the ram at 320 when FSB is at 200, also referred to as 5:4 ratio), set your FSB to 250. This will clock the ram at 400. You should be able then go further.
This is what I have done, the performance setting is set to slow, and even right now I have CAS 3 set in the bios but cpu-z still shows its using CAS 2. Using 333MHz DRAM clock with 250MHz FSB is stable at all default voltages, but anything above those wont work, no matter what voltages. If I set the FSB to 255, it wont be stable anymore, not even with 1.7v vcore and 3.3v memory voltage. Even setting the DRAM clock to 266MHz wont be stable with 255FSB. Also, running a lower FSB with a higher memory clock, so that the FSB is lower but memory goes above 200MHz wont be stable no matter what.

Similar Messages

Mixing Ram with different CAS latencies in K7n2 Delta-L?

I have been using 512mb Kingston Value Ram in my computer, pc3200, with CAS latency of 3.0. I just purchased some Corsair value select 512mb ram pc3200 with CAS latency of 2.5. I know you are not supposed to mix ram with different speeds (like 400 vs. 333) but does it matter if the CAS latencies are different?
I'm running an AMD XP 1800+, K7n2 delta-L, nforce2 motherboard from MSI. Someone at a computer shop told me they tried mixing Kingston 3.0 CAS with Corsair 2.5 CAS, and said his computer wouldn't even post. So I'm wondering if this is an isolated problem, or you will always run into this problem if you mix ram with different CAS latencies.
If anyone has experience with this issue, please share with the board. Thanks!
Chris

The age old question, will the components I bought be compatible ? There are those that have bought identical matching memory that didn't work. In my case, I had an ECS K7S5A that used PC2100 Crucial memory, the sticks neither matched (at one time they did, but one stick died and they sent me the closest thing they had.). Neither of these Crucial sticks was identified by a configurator as being compatible with the K7N2 Delta L that I decided to buy. In the end, not only did both sticks work, but I put them in as single channel mode (ram slots 1 & 2), but later changed the configuration to dual channel mode (ram slots 1 & 3, even 2 & 3). It worked flawlessly in all three configurations. Sorry for the long answer, but in essence, there are no guarantees and your worries will drive you crazy. When memory is mixed, you reduce the likelihood of compatibility, even when you go beyond the recommended products that were specifically identified.
That guy at the computer shop, did he ever indicate or isolate the true reason why the memory wouldn't work ? Maybe, maybe not. I would think with a disparity in memory, the bios is the key to setting the settings for the worst stick of the bunch. Then again, the products you get might overclock to what the better sticks run at. My assumption is that mixed sticks, the bios retards settings to this in "auto" mode. When you force it manually, it may work or it may fail. One thing you oughta know, each and every stick has the manufacturers id encoded onto them at the very least, just like the firmware on other items indicates a manufacturer code and other data that allows these things to be compatible. So know you face that battle going in with any of them. If the bios programming doesn't allow it to work, from that perspective, there'll be problems.

BUG with Memory CAS-Latency with MSI i848P Neo-LS BIOS

I have a bug with MSI i848P Neo-LS BIOS. I try many MSI i848P with same trouble : the CAS Latency is always set to 2.0 even if the memory is CAS Latency 2.5.
It doesn't depend on PSU or others things (graphics card,...).
Try with Pentium 4C 2.6 or 2.8
But I have just one brand of memory (but many different sticks). Chips reference are VT56DD32M8PC-5 (256 or 512 Mb). This memory are reference as Cas Latency 2.5
If I set memory timings on SPD or manual : same result !!!
If I set memory speed on AUTO or 400 MHz : same result !!!
If I set other timings, then they are save correctly (ie : RAS# precharge set to 3 or 4).
I check timings with latest version of Memtest86+ V1.0 : http://www.memtest.org/
and of course, I get many errors.
The same memory tested on others mobo, give good results.
I try Windows XP installation and I get.... blue screens.
With some memory sticks : I have this message "memory timing too tighly",
if I press F1 to continue: then I get a memory cas latency of 2.5 with memtest86+ and then no error.
I try BIOS revision 1.0 (default) and 1.2: same result !!!
So, as I said before, I think this is a bug with the BIOS. I agree that a BIOS cannot detect correctly all kind of memory, but if you set memory timings manualy, then it must be set as you want ! ?
Any idea...
Thanks

H0 Alex,
You are correct.I have the same problem with my 875p neo lsr on bios 1.9. TH0S 0S B0OS BUG.but everyone says your psu is not enough or your rams isnt on the MSI Memory Compatability List.
why all of rams I try give same result?
MS0 boards works only with 10 or 20 ram.you don't say customer why you use this rams?
why in asus boards many os these rams working properly.This rams isnt on the MSI Memory Compatability List.but working.I try many no name rams and results are very good in all of the tests.
In my opinion MS0 bioses doesnt work good enough.
You don't drive a car.Car Drives you.

DRAM Clock Settings and SDram Cas latency

: 8o Just got my KT3 ULTRA 2 Socket A Motherboard. When I turn on the computer, in the POST test it says:
DRAM Clock = 266MHz
SDRAM Cas Latency = 2
I checked the cmos and the latency is set at 2 , but what about the DRAM Clock? Please help for I am a newbie. Thanks

If your CPU is Athlon XP 2700+/2800+, the FSB is 166Mhz, the DRAM frequency is HCLK (166Mhz).
If your CPU is Athlon XP 2600+ and below, FSB = 133Mhz, then HCLK = 133Mhz, HCLK+33 = 166Mhz
If your CPU is older Athlon or Duron, FSB = 100Mhz, then HCLK = 100Mhz, HCLK+33 = 133Mhz, HCLK+66 = 166Mhz.

KTV4 DDR266 memory CAS latency compatability - question

I am planning to upgrade my DDR266 RAM from 512MB to 1GB by adding a 512MB module.
The current module is CL2, but all available upgrades are CL2.5. Supliers all recommend CL2.5 modules. Will I have a problem if I mix CL2 with CL2.5? I have ask a couple of memory suppliers about the CL compatability, but they will not express an opinion.
If there is an issue, I was wondering if setting CAS# Latency in BIOS to CL2.5 will help.

Hello,
You should never mix memory modules that are different.
Yes it can work fine but for optimum performance you must match.
Sometimes both modules will not work together
PC will BSOD a lot
Or it will be ok.
Yes setting the memory timing to CL=2.5 in the BIOS will make the other memory module run at CL=2.5 but there are more timings that just the CAS latency.
All must be the same/old module must be capable of running at new modules timings.
Will the new module be DDR266?
I would recommend you get some new sticks, PC3200 (<will run at 266DDR) 2x512MB and sell the old one.

Does Cas Latency really make a difference?

I have a MSI K8N Neo2 setup (AMD64 3500) and I am inquiring if memory latency effects are really noticible or not during heavy gaming or creating home movies for DVD's. Currently, I have two sticks of Corsair Value Select 512MB DDR PC-3200 (VS512MB400). It has a Cas latency of 2.5. Is there any good noticible performance reason, I should trade up and buy some better performing memory. If so, does anyone have a tried and true favorite with the K8N Neo2? Any thoughts? I have never overclocked, I just run at stock speeds. Perhaps the performance gain is not worth the money?
I also have:
eVGA geforce 6800NU
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Sony DVD burner
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Netgear WG311v2
4 case fans
1 GB PC-3200

Spread Spectrum Modulation was invented to reduce interferences of high order
harmonics of the bus frequency. The theory is that, because every wave form
generates higher order harmonic waves or Obertoene, accumulation of the latter
can result in interference with the original signal.
One way to avoid this problem is to subject the base frequency to a slow (ca 100,000 clock cycles) modulation,
meaning that the FSB varies between e.g. + and - 1% of the nominal value.
In older boards, usually two different settings were available,
either centered around the nominal value or set with the nominal frequency as the maximum (low modulation).
Most current boards employ the centered modulation.
This is, at least, the official version of Spread Spectrum Modulation.
In reality, there are different reasons for its implementation.
With increasing operating frequency, electronic components emit electromagnetic interference signals (EMI).
EMI, on the other hand can cause interferences with other devices and is,
therefore, subject to regulation by the FCC which limits the signal amplitude according to its guidelines.
Any device exceeding the maximum allowable signal strength will not gain
approval by the FCC and can, therefore, not be marketed.
In order to understand the reason for SSM, it is necessary to know how the FCC
tests EMI.
Basically, the testing device is a radio receiver and the testing is done by sweeping
its receiving frequency through the frequency range of interest and measuring the
interference with the video and audio signals. The bandwidth sensitivity of the
measuring device is in the order of about 1 MHz.
If the operating frequency is modulated to spread over a bandwidth of typically
4-5 MHz, the same will happen to the EMI spectrum and,
instead of showing a sharp peak, the spectrum will be spread to a more or less
Gaussian bell shape.
In this case, the amplitude will be, of course, substantially smaller, that is,
in the order of 1/3 - ¼ of the original peak.
The energy, however, will be the same. On the other hand,
the measuring instrument with its bandwidth limited to only 1/4 of the spread will,
consequently, only see 1/3 to ¼ of the EMI.
Therefore, the system will obtain FCC approval even if it exceeds the guidelines.
Recommended Settings
If running at stock setting, enabling Spread Spectrum Modulation (SSM)
may reduce EMI, and cause less interference with wireles communication devices.
Under all conditions, enabling SSM may cause a system to crash.
This is especially true for overclocking, simply because with the high multiplier values employed now, even a 0.5% modulation up and down can cause
differences up to as much as 10 MHz clock speed within one modulation cycle.
In other words, if the CPU is already operating at its limit, increasing the clock
speed by another 10 MHz may be fatal.
Therefore, for any overclocking, SSM should be turned off.
Another side effect of SSM is that it can interfere with the clock generator.
This means that, instead of merely initializing SSM, it is possible to enable FSB settings that were never supported by the manufacturer.
Examples are the Tyan Trinity 400 where disabling SSE results in an actual bus
speed of 90 MHz instead of the selected 117 MHz or the MSI 6309 where FSB settings of up to 200 MHz become available.
The reason is that activating SSM can cancel out the FSB setting since there
can be a pin address overlap on the clock generator chip.
(from lostcircuits.com)
Lets say your CPU is putting out EMI , its all concentrated on one "channel/frequency" on the spectrum.
What spread spectrum does is broaden that out to multiple channels/frequencies so it isn't as "potent" or interupting.
http://www.rojakpot.com/default.aspx?location=8&var1=0&var2=115
This is interesting.
Fsb spread spectrum enabled can cause internet dropouts.
http://www.asus.com.tw/support/faq/qanda.aspx?KB_ID=84823
If i can access it in bios i always have it disabled in any computer i'm maintaining.

CAS Latency 2 Reverts To 2.5

My RAM is designed for 2.5-3-3-7. I've already changed it to 2.5-3-3-7, but was recommended by someone else with similar memory that I try changing the 2.5 to 2, for more performance. When I set it to 2 it boots and runs fine, but CPU-Z and Memtest86 report it as 2.5 still. The BIOS definitely reports it as 2.
Why?
Is it true that the CAS Latency makes little difference on my system? Why is this?
Specs:
Intel Pentium 4 2.8e HTT @ 3.26GHz
Thermaltake Spark 7+ Xaser Edition A1715 CPU Cooler
MSI 865PE Neo2-PFISR motherboard (BIOS ver. 3.8)
2x512MB OCZ PC3700 Gold Edition Revision 3 Dual Channel Enhanced Latency DDR @ 466MHz
Built-by-ATI Radeon 9800 Pro @ XT 128MB DDR 256-bit @ 415/744 (Catalyst 4.12)
Arctic Cooling VGA Silencer Revision 3
Creative SoundBlaster Audigy2 ZS Platinum
Cyber Acoustics CA-4100 4.1 Surround
Maxtor 6Y120M0 120GB HDD 7200RPM SATA150 8MB cache
Sony DDU1612 40x/16x DVD-ROM
Sony CRX230ED 52x/32x CD-RW
Enermax Noisetaker EG475P 470W PSU(+3.3V = 34A, +5V = 40A, +12V = 33A)
Ultra Dragon ATX Mid-Tower Case
Windows XP Pro SP2

Sounds like CPU-Z is reading the IC Chip settings and not BIOS settings.

DDR 3200 Cas latency Settings

I have 2x256 platinum corsair 3200 Low Latency twinx memory. I changed the latency settings to 2.2.3.6. and my pc is now running faster. Does anyone Know the optimal settings I should be running them at? Also what is the Burst speed in the bios.( This is listed right ofter the cas latency section in the bios. I have a choice of 8 or 4 what should I choose

If your system is running faster-you should be happy. Timings vary from system to system depending on bios version and quality of ram. Ideal settings are 2-2-2-5. In reality this is hard to achieve with stability on a Canterwood/Springdale chipsets-especially in the higher peformance modes (ultraturbo). Also ras to cas seems to be far more stable on these chipsets when set to 3(my gut feeling is that PAT is somehow affecting this setting). Memory manufactures like Mushkin recommend that 6 be used instead of 5 for btter stability and less potential data corruption. Finally from what I remember about burst length 4 is more stable than 8 but 8 allows for more speed. I do not think there is a big drop off when using burst 4 as opposed to 8-you would have to use your own testing. Your settings are fine as long as your system is stable. My one question is how sure of you that what the bios is reporting is what your memory is actually running at. This has been a "known" issue with the various MSI bios's. Use and independant reporting tool such as CPUZ to check the validity of your timings. Also as you tighten your timings it is advisable to raise your Vdimm-2.65-2.80 seems to do the trick-especially if overclocking.

Memory settings? Corsair XMS Extreme - Cas Latency: 2-3-2-6 T1

I've been trying to make sense out of the memory settings in the Bios. I read a bunch of posts but I'm still a little confused...
Here is my memory:
2x512Mb DDR400 - Corsair XMS Extreme - Cas Latency: 2-3-2-6 T1
TWINX1024-3200LLPT
on MB: K8T NEO-FIS2R
what should be the settings as well as voltage for this?
bank interleaving
burst length
CAS (CL)
TRCD
TRAS
TRP
right now I have:
CAS: 2
TRCD: 4
TRP 2
DDR Volts 2.65
thanks
TZ

I'm running the same memory as you are with a different colored heat spreader, Corsair XMS 3200LL. My system has worked fine from day one with the standard SPD settings that are 2-3-2-6-1T at the default voltage. Unfortunately, Corsair is really hit or miss since all the BH5 chips are gone. Our RAM is built on CH6 chips (assuming v1.2 RAM). There's a great Athlon 64 Special Report on setting RAM timings for the Athlon 64 on Mushkin's website. Luckily, I haven't had to change anything, but the article may help you out.

Paramenter Value Case Sensitive Setting

Is there a setting in the pref.txt file (or any place else) to change the actions of the case sensitive setting for entering parameter values? Turning it off/on. Changing the case sensitive setting in the condition that contains the parameter does not modify the parameter value entry window functionality.
Thanks,
Jerre

Hi Jerre
I'm afraid there is no preference that can be set to control the casing of the values keyed in a parameter. You would have to do this yourself by embedding the value of the parameter into a calculation and use UPPER or LOWER accordingly.
The option you are referring to controls whether Discoverer should literally take the value keyed in the parameter as the filter for the condition or not. It does not change the casing of the parameter for other uses.
Best wishes
Michael

Why DDR3 @ 1333MHz on Core I7 iMac + CAS Latency

Hello,
I've just ordered an iMac 27" Core i7 (mid-2010) with 4Go.
On Intel's i7 page, I read :
http://ark.intel.com/Product.aspx?id=37148&processor=i7-940&spec-codes=SLBCK
Memory Specifications
Max Memory Size (dependent on memory type) 24 GB
Memory Types DDR3-800/1066
# of Memory Channels 3
Max Memory Bandwidth 25.6 GB/s
Physical Address Extensions 36-bit
ECC Memory Supported No
On the other hand, Apple says that memory upgrades shall match the followings:
* PC3-10600
* Unbuffered
* No parity
* 204 pins
* *1 333 MHz*
* SDRAM DDR3
My questions are:
1° Why shall we use 1333MHz since i7 only supports 1066MHz ?
2° As regards CAS Latency, if I add 2x2Gb with faster CAS, will they work at their own CAS Latency or at the stock 2X2Gb's ?
3° If I decide to leave one slot free, I can simply add 1x4Gb. Will this impact the dual channel performance of the stock 2X2Gb or will this perform as before ?
Thanks a lot for your help !
Cheers,

Hi yoms
Welcome to Apple Support Communities
{quote:}1° Why shall we use 1333MHz since i7 only supports 1066MHz ?{quote}
Do yourself a big favor and stick to [Apple's Memory specification,|http://support.apple.com/kb/HT4255] those that have not, have had all sorts of problems ranging from slow performance, Kernel Panic's, failure to boot, damaged slots and fried memory controllers.
{quote:}2° As regards CAS Latency, if I add 2x2Gb with faster CAS, will they work at their own CAS Latency or at the stock 2X2Gb's ?{quote}
When [Installing or replacing memory|http://support.apple.com/kb/HT3918] you can have 2 or 4GB modules in opposing banks, but they all must be the same latency and speed.
{quote:}3° If I decide to leave one slot free, I can simply add 1x4Gb. Will this impact the dual channel performance of the stock 2X2Gb or will this perform as before ?{quote}
More ram will help, but [Matched RAM on Intel Macs|http://guides.macrumors.com/MatchedRAM_on_IntelMacs] always provides the best performance.
Two highly recommended third party ram suppliers are [OWC|http://eshop.macsales.com/shop/memory/iMac/2010/DDR321.527] and [Crucial|http://www.crucial.com/store/listparts.aspx?model=iMac%203.6GHz%20Inte l%20Core%20i5%20%2827-inch%20-%20DDR3%29%20Mid%202010&pl=Apple&cat=RAM]
Dennis

Trying to find lowest latency setting for FMS 3.0 live streaming app

Hi,
I work for a technology company in the agricultural industry,
and we recently bought Adobe FMS 3.0 for live streaming of an
online auction application. Initially the tests were ok, but the
stream latency is becoming a real issue. It starts at around 1s
delay, which is barely acceptable, but an hour into the sale it
stretches to 2-3s, and more. This is becoming a real deal breaker
for the Flash solution that looked very promising at the beginning.
We need to find the absolute lowest latency setting for the
live streaming application supplied with FMS3.0.
Low latency (1s max) and stable latency has highest priority,
more important than picture quality or uninterrupted streaming.
How can we achieve this? Are there any settings where I can
tweak the stream latency?
I am not a Flash expert, but I can find and modify the
configuration files on the FMS Windows 2003 server.
Any help would be immensely appreciated.

On server side:
FMS installs itself with default configurations optimized for
Max CPU efficiency. Reducing/shutting-off FMS publisher queues
using Application.xml config should help in removing the delay that
you experienced.
<Application>
<StreamManager>
<Live>
<Queue enabled="true">
</Queue>
</Live>
</StreamManager>
</Application>
Changing default setting to <Queue enabled="false">
disables live publisher queues & aggregate messages ad
therefore "the delay". (the delay should be reduced to <100 ms
for a perfect kind of network or LAN)
--> On client side: Do NOT use NetStream.setBufferTime API
at all ! i.e. do not set any buffer on client side.; Flash player
(upto 10, the current version) would try its best to keep the
buffer around 0.1 seconds, which is the default value.
OmicronPersei8,
Which publisher are you using to publish the live stream?
Sometimes , it is possible that a some fault at stream publisher
may make buffer at flash player grow.
I hope this would help !

Check memory cas latency ?

I have a 15" i5 MBP from 2010 (MacBookPro6,2) with 4 gb of 1066 mhz ram at cl 7. I want to upgrade to 8 gb, but the local computer stores here only carry 2x4gb of 1333 mhz ram at cl 9. My calculations show this new memory should be able to run at 1066 mhz with cl 7. I've installed it in my MBP and it's running fine, but is there a way to tell if the MBP is running the new ram at cl 9 or cl 7 ?

I've never seen these questions asked here before, and I think therefore it's safe to say that very few Mac users ever give a moment's thought to the stats you're asking about. As a general rule, if it works, we use it. If it doesn't, we exchange it for something that does.
Most if not all Macs will slow faster-than-spec RAM down to the speed of the specified modules. Your machine is undoubtedly running your RAM at 1066MHz. As for cas latency, who knows? Apple's specs say nothing about that, and never have.
You will usually save a lot of money by buying RAM online rather than from a local store, and you'll usually be able to find the RAM that is specified for your machine.

Cas latency on one 6758

Hello Excuse for my English but I use a translator and I am French I have a MSI i875p néo (6758 in pcb1) since several me and I tested all the left bios. Currently I have the bios 2.2 Since I have this CM, I noticed after having tested different barettes from memories (to corsair, ocz, adata....) that it is impossible to modify CASE LATENCY whereas the other parameters report can modified and thus the parameters case latency is always that of the SPD what want hard that if I have of the memory with a case latency of 2, I cannot put it in of 2.5 or 3! Who can me help itself to solve this problem bus MSI FRANCE never answers the mail!!! Thank you

hope this makes sense:
il est juste quelque chose qui est erronée avec ce conseil, vous changement biseauté les synchronisations très bien, à moins qu'ils fassent quelque chose vraiment bonne et changent le bios pour faire ainsi.
si vous voulez changer les arrangements, vous serez meilleur outre d'obliger un nouveau conseil plutôt que de d'attendre MSI à fixer le problème, tel qu'un abit maximum 3
hehe go the translator!

CAS Latency of Default RAM

I have 1GB Apple DDR2 SO-DIMM 667Mhz 200 Pin RAM. I will upgrade to 4GB with CAS Latency 4. What is the current CAS latency of my current ram. Also, my ram is 2 x 512 MB and is by Apple (it came with my mac). I have White MacBook (Late 2007).
Thank You.

Just purchase any RAM that meets the specifications given in the computer's user manual. You need not be concerned about buying lower latency RAM as it isn't worth the extra money.

Cas latency setting

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