Stereo Tool

Building a new pc capable of running two instances of ST for FM broadcast. I currently have a E7400 Core Duo that *just* comfortably runs one instance perfectly, so I assume an I5 will quite comfortably run two instances.

If possible I'd like to be able to accommodate future ST versions (that may have increased CPU requirements) for at least a while!

Is there any significant performance advantage with two ST instances using an I7 2600k/2700k vs an I5 2500k CPU? And is overclocking recommended? It's been suggested to me to use Intel Z68 based boards (i.e. Intel Desktop Board DZ68ZV) to maximise likely reliability, plus I'll be running motherboard RAID1 for system drive redundancy - with Win XP Pro or Win 7. I'd welcome suggestions! Cheers AJ

There are a few changes planned that will really increase the CPU load:

- Composite clipping (FM only). Will probably take about 2-4 times as much CPU power as the current Loudness filter!
- Quality problem with window shapes. Definitely an optional improvement. If I make it, it wil nearly exactly double the CPU load.

For current ST what you might need most is CPU affinity option in ST, eg ST1 Affinity-core1,2 and ST2 Affinity-core3,4.
Also you can do that by editing shortcut so ST will always use defined cores. (i forgot command)

- i7 2x00k processors are all mostly good, and there is no big diff. Actualy there is, but that varies for series and "engineer samples". If you know how to overclock and still be 100% stable, why not? But i think that you don't need that for now.
- First motherboard you'll look is ASUS.
- SSD ?

And for future ....

Thanks Hans, that's useful to know.

http://www.cpubenchmark.net/common_cpus.html
E7400 - 1894
I5 2500k - 6745
I7 2800k - 9415

$120 extra for the I7 2800k over the I5, so easy decision - I'll get the I7. It's CPU benchmark is ~5 times the E7400 (which just runs one instance now). From what your saying, it sounds like the I7 overclocked may or may not run two instances properly with both your planned improvements enabled. I'd best get a decent power supply and investigate extra cooling - with a bit of luck it may just manage it.

Would there be likely any long term reliability issues running an I7 overclocked and maxed out 24/7 like that?

Thanks Bojcha. I had just thought about two standard HD's using the motherboard RAID1 on those Intel boards. Any particular reason/model you recommend from Asus? While little cost difference now between small SSD system drives and entry level HD's, I was wondering if the long term reliability on Win XP (5-8 years etc) maybe better with the HD's installed. I didn't envisage any relevant performance improvements with ST using SSD's, except faster boot times, which won't really impact me in normal circumstances. Would those assumptions be right? Cheers AJ

It is possible that I'll find a different solution for these changes, which doesn't result in such a high CPU load. But of course I don't know that yet...

The Omnia already contains both features and it has an i7... Usually loaded upto about 60%, but there's only 1 composite output (there are several other chains in it though, so I think in total it might be a bit more efficient. Which can partially be explained by the fact that it has a much longer latency; if I would increase the latency a lot I could also reduce the CPU load at some places).

- In my expirience ASUS are good boards. You can always found some 'problematic' model but overall they are best for me.
- About SSD, yea, good question, they are just recently started to be used widely. I have 2 in Raid0 in my PC and i did't have any problems for now (only for XP you need special partition formating before OS instalation). Anyway if boot speed is not important i would also go on HDD or Raid1. Actually we still have on our two transmitters HDD. I speed up XP as possible as i can. Used my stripped XP instalation (say if you need ), disabled non-important thing, etc.. and it's reasonable fast.

thank you both for that useful info.

As the pending new ST features will be CPU intensive, a user option to further increase latency and thereby minimise CPU load would be welcome.

While some users require low latency, I have a potential application where it would not matter if the latency was a few seconds. And I think the US IBOC HD system adds padding seconds of delay into the AM & FM analog chain in order to allow digital/analog receiver blending in sync. In that application, a processor that has a lot of latency in its FM composite stage is not a problem at all!

Cheers AJ

Yes, that's true .. some FM stations intentionally add latency to sync with HD .. but always will be needed low latency too.
In current ST you can have up to 5sec latency for both FM and normal outputs. Using asio it will always stay at adjusted latency.