Stereo Tool

Will ST with composite clipper run on a Core 2 quad Q 6700? I notice several post where users are running core 2 duo (probably clocked).I have a eng friend wanting to set up a box on the cheap.thanks

Right now i am running Full FM preset on E5400 slighltly clocked from 2,7 to 3.0 with new clipper strictness at 18 with Declipper ON.
Q6700 - http://ark.intel.com/products/30790/
E5400 - http://ark.intel.com/products/40478/
That CPU is 2.66GHz but also with 8MB more cache and higher FSB, also 65nm so more heath.

http://www.cpubenchmark.net/
Look at this, and calculate the performance per core. ST uses only 2, if each core is fast enough it should work.

http://www.cpubenchmark.net/cpu.php?cpu ... 40+2.66GHz

Looks like it would work fine.

Q6700: 3360, divide by 4 cores gives 840
E5400: 1606, divide by 2 cores gives 804, but it's overclocked to 3 GHz so *3/2.7 = 893.

Of course, the CPU is not the only thing that affects the total execution speed - memory speed is also important, and CPU's might behave differently due to different cache sizes etc. This benchmark is only an indication.

I actually would never have expected it to run on that E5400... My laptop is an i7 2630QM (2 GHz):
i7-2630QM: 5643, divide by 4 cores gives 1411.
Which is quite a lot more - I should be able to run it even in single core mode based on this. But I can't. On the other hand, in multicore mode I have enough headroom to push the declipper quality settings close to the maximum, which has quite a big effect on the CPU load.


If latency is not an issue and you're running with Latency set to 4096 samples, you can always reduce the Quality slider quite a lot - at high latency settings this has very little effect on the audio. If you reduce Quality to - say - 50%, the CPU load is 75% of the normal CPU load, which helps a lot.


Just for comparison: My old Pentium 4:
Intel Pentium 4 2.40GHz: 241

Using your guide to the PassMark figures:

I am running the software on an Intel Q9650 which rates 4,314 or 1078.5 per core. I want to build a rackmount PC for the software and was looking at putting in an i3 3220 which rates 4,239 or 2,164.5 per core (only 2 cores). An Intel i7 3770K rates at 9,630 or 2,407.5 per core.

As you're saying ST SA only uses 2 cores, is the i3 3220 the better choice here?

Thanks,
Clipper

The i7 is still slightly faster per core! But probably a lot more expensive too. By the way, one thing that makes these comparisons very difficult and unreliable is Hyperthreading - if a PC has hyperthreading it will score higher in these benchmarks but it will have nearly no effect on Stereo Tool.

Now, if the price difference is small I would probably go for the i7 since there's more room for future improvements. No idea if ST will ever use it though.

I heard from someone who is using the composite clipper on a Q9650, he says it's running properly. But he does have a lot more latency (8 ms) due to the longer time needed to perform all the calculations. I might - maybe - add a 4 core version some day to reduce this effect (not planning to do this right now though). On a faster CPU the effect will be much less than these 8 ms. And even if I would do this, it won't help for most other filters (most filters use 1 core per channel, and there are only 2 channels in a stereo signal).

There's another thing that I want to do which reduces artifacts when using lower latency settings, which will cause the CPU load (and number of cores used) to double. But I don't know if I'll ever add that to the software version.