XXHighEnd

Ultimate Audio Playback => Your questions about the PC -> DAC route => Topic started by: ivo on May 22, 2010, 11:53:54 pm



Title: Running QAP on Atom CPU???
Post by: ivo on May 22, 2010, 11:53:54 pm
Hi all,

If there is anybody who is satisfied with running XX in QAP mode via KS on Atom CPU, please call in and share your setup details! I want to know how much the Atom gets utilized in this mode???
I would like really to have a proof that it is not possible to listen normally the music on such a hardware using XX.. Otherwise I am going to buy one. :)

Thanks,
Ivo


Title: Re: Running QAP on Atom CPU???
Post by: PeterSt on May 23, 2010, 08:23:05 am
Ivo,

If you search the forum for Atom, I think you will find some topics, but maybe they are not useful. But take the experiences fom Ed Linssen as an example; I change something, and suddenly he has problems. Should be my fault (or W7's) but anyway things are far more critical.
Or Mani, who as far as I am concerned tried one, bought a next, and now again bought another (a few weeks back). But why ? because he wants to squeeze out the best (lowest) latency. And this just doesn't happen with a processor which is not the best (because there are better).

So you will *know* you will run into limits before others do. Maybe not today, then tomorrow. Tomorrow because of new developments, like Double Octo Arc Prediction (16 x) which is a fact for me today (but that depends on your DAC of course). There will be more.

Mani might be the best to explain a bit.

:scratching:
Peter


Title: Re: Running QAP on Atom CPU???
Post by: manisandher on May 24, 2010, 10:27:03 am
Yes, Peter is right, within the last 6 months my PC for XXHE has evolved as follows:

1. Sony laptop - I was happy for many years with this
2. Atom-based PC (following the design on computeraudiophile.com called C.A.P.S.)
3. E8600-based PC in Zalman totally silent (no moving parts) case with Gigabyte mobo, fast memory and one SSD
4. i7-based PC (hyperthreading off) in Zalman totally silent (no moving parts) case with Gigabyte mobo, ultra-fast memory and two SSDs

This evolution has been soley down to using QAP in KS Special/Adaptive mode. Only 3. and 4. can really cope well with this - especially if you have any hi-res FLAC files which take just ages to pre-process on slower machines.

BUT...

I still use the Atom-based PC in my office, where I use it mainly to listen to background music. It works perfectly well in KS Adaptive mode with NO upsampling. With the hiFace, I have the buffer set to 1024. One thing I really love about this machine is that I can leave it on all day knowing full well that its consuming next to no power and will remain totally cool - its incredibly efficient.

EVEN MORE IMPORTANT...

In my office, I use an old MF x24K DAC. Even though this DAC is 24/96 cable, I prefer NOT to use DAP with it, as it sounds 'muffled' compared to straight 16/44.1. (I am convinced this is down to its use of delta-sigma chips.) So, if you have a delta-sigma DAC, I think an Atom-based PC could work well... but just don't use DAP or QAP.

My one single caveat to all this is: if you are interested in buying the NOS1 DAC in the future (and I think anyone who wants absolutely the best SQ possible should be!) then DON'T go for an Atom - you won't be able to use Double-OAP!!!

Mani.


Title: Re: Running QAP on Atom CPU???
Post by: Telstar on May 25, 2010, 08:22:20 pm
3. E8600-based PC in Zalman totally silent (no moving parts) case with Gigabyte mobo, fast memory and one SSD
4. i7-based PC (hyperthreading off) in Zalman totally silent (no moving parts) case with Gigabyte mobo, ultra-fast memory and two SSDs

Any difference in SQ between the two?
Peter told me that there isnt much more resources involved in octal AP. And i hope so.


Title: Re: Running QAP on Atom CPU???
Post by: ivo on May 25, 2010, 08:45:34 pm
BTW, I have tested my HiFace in QAP in KS mode on E6300 and it works well. I can go down till the lowest value of Dev buffer (32) and CPU is utilized for about 15%. The sound is really better if Dev buffer = 32 rather than 1024. Of course the latter does not utilize the CPU at all.

Based on the above, I am starting to move towards i3-530 CPU. Seems like it should be good enough to handle QAP in KS mode under windows 7 and hopefully any other xAP in the future.

Ivo


Title: Re: Running QAP on Atom CPU???
Post by: manisandher on May 25, 2010, 08:48:55 pm
Not an obvious difference in SQ, but I haven't really AB'd them, as I don't have two identical soundcards. But when I get hold of the two NOS1 DACs :), I will AB the two machines.

However, the i7 machine achieves a lower Q1 in Special mode than the E8600 machine - ~90 vs. ~150 samples (IIRC). I'm not sure this is down to processor power though - I'm underclocking the i7 to keep within the 70W max. TDP specified for the Zalman TNN300 fanless case. Another big difference between the machines is the memory - one has G. Skill DDR3-2200 modules, the other G. Skill DDR2-800 modules.

BTW, both machines run at around 40 degrees C and easily pass the Prime 95 test...

Mani.


Title: Re: Running QAP on Atom CPU???
Post by: manisandher on May 26, 2010, 11:15:58 pm
If there is anybody who is satisfied with running XX in QAP mode via KS on Atom CPU, please call in and share your setup details!

Ivo,

With 0.9z, I'm getting good 'performance' from XX on my Atom PC with hiFace. With the buffer set to 256 (or higher), I can use the following settings:
Special Mode - Q1=-1, (8 samples!)
Adaptive Mode - Q1=1

But loading is still painfully slow... especially hirez FLAC files. As might be expected, graphics are also very slow.

BUT... it works!

Mani.