Multicore Desktop Processors and their desktop boards: Any risk to audio quality?

[chane]

With the end of the Window XP security updates, among other factors,
I needed to take some time to replace my ancient tower pc, with one the runs either an Intel Ivy Bridge 4 or 8 core or the latest Haswell 4 core processor. To minimize fan and/or electrical noise, the better choice appears to be the low power versions of the processors Ivy Bridge
(http://en.wikipedia.org/wiki/List_of_Intel_Xeon_microprocessors#Xeon_E5-2xxx_v2_.28dual-processor.29 )
E5-2630 v2 (6 core, 2.6GHz, LGA2011 socket, 80w), E5-2630L v2 (6 core, 2.4GHz, LGA2011 socket, 60w), E5-2428L v2 (8 core, 1.8GHz, LGA1356 socket, 60w)-or the new Haswell
(http://en.wikipedia.org/wiki/List_of_Intel_Xeon_microprocessors#.22Haswell.22_.2822_nm.29 )
E3-1285L v3 (4 core, 3.1GHz, LGA1150 socket, 65w) and http://en.wikipedia.org/wiki/Intel_Haswell_%28microarchitecture%29#Desktop_processors
i7-4770S(4 core, 3.1GHz, LGA1150 socket, 65w), and i7-4770R(4 core, 3.2GHz, LGA1150 socket, 65w).

My chief priority will always be audio signal quality (i.e. editing of uncompressed wav files of music CD tracks for playback via USB
or a balanced AES card feeding a high performance external DAC).
But I also would like to eventually use this computer for DVD as well as more demanding BluRay movie disc editing.

Though presently having no hands on experience and minimal knowledge of computer video editing, I do know that the most time consuming phase of the process is recompression of the edited video back into the BluRay movie disc format. Depending on the software and hardware resources, recompression could take anywhere from 45 minutes to well over 90 minutes. So I thought that a new pc with one of the above six or eight core model processors and 16GB of RAM, together with the right software apps, might significantly reduce BD compression time-perhaps to as little as 30 minutes.

Again, however, my primary concern is audio quality. Therefore, compared to the ubiquitous dual core processors, could using four,
six or eight core Ivy Bridge or the new Haswell four core processors somehow pose any degree of risk to audio quality, in one or more ways?

And, of course, of particular interest would be any related incidents involving any of the specific (low power) processors listed above, and/or desktop boards they were used in.

Before I make this computer purchase, any advice or referrals would be greatly appreciated.

Thank you.

 

[GlacierFreeze]

Therefore, compared to the ubiquitous dual core processors, could using four, six or eight core Ivy Bridge or the new Haswell four core processors somehow pose any degree of risk to audio quality, in one or more ways?

No

 

[Maximilian]

No

 

[Yuriman]

I see no reason to opt for the slower / lower TDP chips, either. It's a non-issue.

 

[coercitiv]

My chief priority will always be audio signal quality (i.e. editing of uncompressed wav files of music CD tracks for playback via USB or a balanced AES card feeding a high performance external DAC).

Sounds to me like you are always performing the D/A conversion on an external circuit, with separate power supply. If that is the case, the CPU you choose is of little importance.

 

[BSim500]

My chief priority will always be audio signal quality (i.e. editing of uncompressed wav files of music CD tracks for playback via USB or a balanced AES card feeding a high performance external DAC). But I also would like to eventually use this computer for DVD as well as more demanding BluRay movie disc editing.

A few tips:-

1. If you're using digital outputs (coax / SPDIF) fed to an external DAC, nothing should make any audible difference at all! You won't get any digital equivalent of "squealing" or "growling" sounds like the days of old where a bad motherboard capacitor "leaks" into the analogue audio outputs when the CPU load changes, if that's what you mean? Nothing is really going to alter a signal that's in a 100% chain of digital throughout (unless you've got a faulty PSU / motherboard).

2. You mentioned "balanced AES" - may I ask how long is the cable run and for what purpose? If it's a glorified short run interconnect, there's little to no real advantage over unbalanced SPDIF (especially optical which is pretty much immune to RFI / "ground loops" between equipment), etc. I guess what I'm politely asking is - is there a serious requirement for AES over long cables (like a studio balanced microphone setup, etc, between rooms), or is it a case of reading "audiophile paranoia" magazine adverts telling you that you "need" an expensive balanced interconnect between a PC and an amp in case the bits "fall out" of the cable across all of a 1.5-2.0m cable run?

3. Don't bother with a 2.6Ghz 6-core CPU's unless you're doing video all day every day, you're better off with a regular 4-core i5. Many audio editing programs are not that well threaded anyway last time I looked. For moderate video editing, you could get an i7 or Xeon over an i5 for a 20-30% improvement (at much less cost than a 6-core), but how much of that do you intend to do on a regular basis? If you're talking about ripping a few Blu-Ray's a week, you might as well buy a regular i5. I'd only get a 6-core if you did it all day, every day as part of your time-critical job. It's also entirely possible to spend much longer editing than transcoding if your edit involves a lot of cutscenes / transitions / other effects, etc. Are you making your own vids, or simply ripping & transcoding Blu-Ray's to disk to use as a "video jukebox" without any actual editing?

4. 16GB vs 8GB RAM probably won't make much difference to simple Blu-Ray transcoding speeds. It might well help though depending on what length video / audio files you edit with 64-bit Windows + 64-bit editing software (Adobe Premier, etc)?

5. S chips are good to keep heat / noise at the absolute lowest TDP "out of the box", however, with a decent motherboard with adjustable vCore, you can simply buy a regular chip and undervolt it to accomplish the same. I'm into silent PC's myself and have a i5-3570 dead silent rig that never exceeds 59c even at 4.2GHz with very slow spinning 600-700rpm 120mm fans, so a stock 3.4Ghz i5 with a half-decent basic heatsink (CoolerMaster 212 EVO) should post zero problems.

6. SPCR is a great resource for low noise computing. The guys have even built an anechoic chamber for accurate low db noise testing of various components. They do a lot of recommendations for silent heatsink, fans, PSU's, etc:-
http://www.silentpcreview.com/

In my experience, the key to a really silent rig is aggressive undervolting + a HQ decent PSU (fanless or semi-fanless Seasonic X series are great). But for hardware recommendations, I'm wondering what your usage is (hours per day) - and what audio editing software you plan to use? There's no point spending a lot on a 6-core if you only rip 1 Blu-Ray per week or have not very well multi-threaded audio software.

 

[Tristor]

Howdy,

I get what your concern is. The reality of the situation is that audio circuits have improved over time in mainstream motherboards. There was a time when it was exceedingly common to run the analog and digital signals right next to each other which could introduce digital noise via inductance into the analog output signal. Since you're not using onboard audio though, this is mostly a mute point. Either way, these days most boards have these signal pathways isolated, some going to great lengths (check out some of the higher end boards from Asus and Gigabyte for instance) to the point that onboard audio on motherboards is actually acceptable for driving most headphones with decent quality.

Only in extremely poorly isolated boards have I ever heard noise induced because of the CPU action, and the last time that occurred was actually on an ancient single-core processor (Athlon64 3200+) and I isolated the noise down to the RTC. It's much more common to hear motors induce noise (CD/BD-ROM drives or HDDs) than it is to hear it from higher frequency digital sources. For your application the best thing you can do is

1) Get a board that properly isolates digital and analog signal pathways if you intend to use any of the analog outputs

2) Ensure the board has properly isolated PCI-E slots for your external card (some boards will enable/disable PCI-E slots dynamically to support other features on the board, you want your AES-EBU card to be in a PCI-E slot which is wired direct into the PCH or CPU).

3) Do not use an optical drive of any kind or any HDDs in this system. Instead have a separate box that just rips the CDs/DVDs/BDs and if necessary a network-attached storage system (you can do this easily with FreeBSD+ZFS on a second box) which are both in another room. This eliminates both the audible noise of the spinning components as well as the possible inducted noise in your signal pathways from the magnetic fields of the motors.

4) Consider keeping your computer system in another room nearby and wiring through the walls for display, USB, and audio connectivity. This will allow you to turn the room you work into a very well sound-isolated room with appropriate materials on the walls, ceiling, and floor. I don't take it this far personally for merely listening, but if I were also doing editing/DAW functions, I would definitely go this far. I assume you have some sort of studio environment, so you should already have a properly isolated room, you just need to move the computer outside of it.

At any rate, there's absolutely no reason not to get the most powerful CPU you can reasonably afford, especially for DAW/video work, as both are very CPU intensive. It takes a lot of power to work with extremely high sample rate audio files in uncompressed format and then do the additional processing necessary, and video editing and encoding is even more complex. I would say if you're planning to encode Blu-Ray that you not have the expectation of anything being completed in 90 minutes. Some of the encodes I've done using x264farm with multiple systems sharing the load (~30 Intel SB or later cores total) have taken upwards of 3 or 4 days. It all depends on the options you use.

 

[SPBHM]

if your old computer is not something like Pentium 3 with 512MB of ram you should be able to install and use windows 7/8 quite nicely.


if you have an external DAC the MB/CPU is irrelevant for audio I think.