CUDA helps accellerate effects, not playback. Your problem may be that your disk isn't fast enough to sustain playback. You may need a RAID for your media, caches and preview files.
That Q9550 is ancient. That's the first thing I'd replace.
As I said, the activity on the hard disks while playing back at any speed is very low, so I don't see that the problem are the disks. Also the Q9550 may be ancient or not, the fact is it isn't being used to its full 100% capacity. So I guess Premiere is just an example of bad programming practices...
"Bad programing practices"?
What on earth are they when they're at home?
Most people who have playback issues soon realise that their hardware specs simply aren't man-enough for the job.
Well I wouldn't consider a 5 year old quadcore as obsolete. I know CPUs are improved day after day, but if a program isn't able to pull out the 100% capacity of a PC, who's to blame? The PC or the software?
But I see inside this community I won't find the answer. It's just too easy to say "buy a new PC", instead of trying to find out what the real issue is. If someone would tell me "well the CPU isn't using its full capacity for the preview, because THIS and THAT" and it did sound reasonable, I'd be ok with that. But it doesn't seem to happen...
Thanks all for your interest.
PS: I never heard that a PC could be "man-enough". I thought the first computers were women...
If nothing is utilized to its fullest, that does not mean that the components are adequately fast per se. It more likely means that there is a bottleneck somewhere in your system - and it is unrelated to the CPU, disks, GPU or memory per se. Your system might have an excessive number of processes going on, or the motherboard's core-logic chipset and/or onboard memory controller could not keep up with the demands of the CPU or RAM.
With that said, if a system based on a quad-core CPU performs slower than a system based on a much cheaper dual-core CPU, it tells you something: Your system's CPU platform is seriously outdated, if not totally obsolete. That's what I discovered when a Q9450 system performed significantly slower in the PPBM5 benchmark tests (this was with Premiere Pro CS5.5) than an i3-2100 system when both systems used identical disks and GPUs and had equal amounts of RAM.
And though the 9600 GT is technically CUDA capable, it does not have enough RAM on the card to even enable GPU acceleration at all. CS5 to CS6 requires a minimum of 896MB on the card to even enable MPE GPU acceleration at all (assuming that you did the "cuda_supported_cards.txt" "hack"). Premiere Pro CC needs 1GB minimum on the card. It doesn't matter, in this case, as the 9600 GT would have been too slow to be of much use even with GPU acceleration enabled (it has only 64 or 96 CUDA cores, depending on the specific GPU core used).
Thanks RjL190365 for your elaborate and useful answer.
And yes, I tried the cuda hack, with no luck. (pun intended). Well I'll have to get a new PC for christmas. i7 - 16 gigs of RAM and a nice fat graphics card.
I wouldn't consider a 5 year old quadcore as obsolete.
In the world of computers, anything five years old is obsolete.
When I look at the task manager and I do the 3x fast-forward in 1080p (also in 720p for the case, no obvious differences actually) I cannot see any "bottleneck" in my hardware. The HDD/SSD drives are nearly not working, the CPU is about 50% and the RAM is also about 50% of usage.
Unlike Win8, Win7 Task Manager won't tell you much about disk I/O - Resource Monitor is a better tool for that.
Windows 8 Task Manager:
Note "active time", "average response time". Win8 Task Manager is awesome.
Windows 7/8 Resource Monitor:
You still get "active time" (blue graph), giving you an idea of utilization but not "response time".
Have you tried doing a 3x playback test with the SSD you have? Put a video clip there temporarily, and do a 3x playback on it, see if the behavior is the same.
Also, tried a 3x playback at 1/4th or 1/8th of resolution?