What's it like to edit with an RPI of, say, 5?

Question

I've spent quite a bit of time going over the results on the PPBM site. I spent today digging a little more deeply into the RPI figures. Obviously, editing on a machine with an RPI of 1 will give you the best possible experience; the fewest freezes, the least lag, the fastest renders. And an RPI of, say, 20 will be much, much slower. But what if your machine clocks in at, say, 5? You're not at the bottom of the heap, but neither are you close to the top. Does this mean that you're suffering through constant crashes? Do you have to transcode your AVCHD to a different format before editing can even begin? Do you give up entirely on certain effects or limit yourself to just one or two layers? Does scrubbing through the timeline make the baby Jesus cry?
In your personal experience, how slow is too slow? As you slide down the RPI scale from 1 to 5, to 10, etc., at what point does the software become unusable?
Obviously, this is a subjective question, but that's okay, because I'm hoping for some subjective answers.

Answer 1

Clay,
To give you some further insight in how to look at RPI and its merits, or lack thereof, one of the things I'm still struggling with is presenting the test results of the new PPBM6 benchmark in a new format, that makes it easier to interpret where areas of improvement may be with your specific system in comparison to other systems.
Sidebar: This proves to be major hurdle to take, since it requires dynamic SQL queries and calculations of the database and presenting the results in these kind of graphs in a LightBox pop-up window for the selected record.
This may not be the final presentation form, but it will show in an eye-glance what this system does in comparison to other systems.
Short explanation: Each bar shows the rank of this system on a specific test, compared to all other systems expressed as the percentage ranking. So, on Total Time this example ranks at 70%, with 30% scoring higher and 70% scoring lower. On RPI 25% score higher and 75% score lower.
If I look at these results, the overall for Total Time and RPI are quite good for the system in question, but what immediately catches my eye is the excellent Disk I/O results, they are very, very good @ 85%. Additionally, the MPE results are very good @ 81%, but both the MPEG2-DvD and H.264 results are somewhat disappointing with 55% and 64% respectively. So, the overall results are positively influenced by the great Disk I/O performance and to a lesser degree by the good MPE results.
If I were in the dark about this systems configuration, I would guess that this system has a dedicated raid controller with a large array causing this great Disk I/O performance and has a very good video card, but is held back on the other tests by other factors. The fact that H.264 is better than the MPEG2-DVD results shows me that this system is nicely tuned, no superfluous background processes running, is overclocked with a nice amount of memory and is better than a plain quad-core, probably a hexa-core or better, but the MPEG2-DVD results are held back because of the interaction between memory and VRAM, which may indicate an older generation CPU. Also, the degree of overclocking may be limited, increasing the latencies between memory and VRAM.
To go back to my earlier post, if you have to export to multiple formats each day, this is a fabulous result, because of the excellent Disk I/O results, if you have clients looking over your shoulder regularly your video card is great, but if you were to export long timelines from AVCHD to MPEG2-DVD, then you may consider upping memory or overclocking a bit more to make a difference.
Note that this is with the same RPI. Now if you compare different systems, you may find different points of improvement. See for example this presentation form:
Here you see essentially the same info, but presented in a different way.
I prefer this way with the speedometer over the first presentation form, but it is even more difficult to implement, since it entails six separate charts.
Two significant differences in comparison to the earlier chart are the Disk I/O performance, which is lacking in this system in comparison to similar systems and the good MPE performance, which shows a very good video card for this system - but not overall - and which helps the MPEG2-DVD score to achieve nice results. This system is more balanced than the previous example, since the scores match better even when the performance is much lower. Note that the first example showed 55% for the MPEG2-DVD test and this one 51%, but the first one showed a RPI score of 75%, while this system shows 40%. That simply means the first system is pretty weak and this system is very good at exporting to MPEG2-DVD. The second system probably has the better BFTB (Bang-for-the-buck) value of these two systems for exporting to MPEG2-DVD.
Again, I emphasize that RPI is a great way to see overall results compared to similar systems, but you have to delve deeper and investigate individual test results to draw conclusions to help improve your systems performance where it matters most for your workflow.
I hope this helps to explain the value - or lack thereof - of the RPI measurement.
PS. The new PPBM6 results table (you have to be registered and logged in to see these results) shows these kind of rankings in the overview, although not on a scale of 1 - 100%, but as absolute scores ranging from first to last observation.