Carla, what are you running on the ZaReason box?
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| Author | Content |
|---|---|
| Steven_Rosenber Sep 24, 2010 1:36 PM EDT |
Are you running Ubuntu Studio, or otherwise using a real-time kernel? |
| tuxchick Sep 24, 2010 3:22 PM EDT |
Phooey, a missed opportunity to compare! I ran both a stock and RT kernel on Ubuntu 10.04, but forgot to try to meansure any differences. It seems that a multicore processor, especially a beast like the i7, would make an RT kernel less necessary. But it would have been fun to figure out a way to test it. |
| Bob_Robertson Sep 24, 2010 3:51 PM EDT |
I'm very pleased with my first 4-core Phenom, but I can only imagine what kind of snap crackle and pop would come about on an 8-core. Just to check, you did have to send that box back, right? |
| bigg Sep 24, 2010 4:24 PM EDT |
I'm curious if you know how easy it is to upgrade. I'll never buy a Dell given the difficulties (and ultimate impossibility) of upgrading the power supply. I'm gonna say that ZaReason doesn't use weird specs like Dell. I've never been able to upgrade a Compaq either, though maybe that's because I've always bought the low-end Compaq's. |
| tracyanne Sep 24, 2010 5:57 PM EDT |
I'm running the pre-emptive kernel on my quad core laptop (2.6.32-24 preempt). I switched from the generic kernel that gets installed on the *buntus by default, when I noticed that under some conditions, like when I'm running Windows in a VM, that 1 cpu core would start getting used almost exclusively, while the others just idled, and I'd get lockups and the machine would bec ome unresponsive, since switching to the pre-emptive kernel the work load get shared more or less equally between the cores and they seem to fluctuate between about 30 to 80% depending on whatI'm doing. I've noticed a huge improvement when recording my guitar playing, Audacity used to have a huge amount of latency so much so that it was impossible to record addition tracks (I'd estimate anything up to 100 milliseconds), Now recording multiple tracks works quite well, I've also got the RT kernel installed, but haven't got round to testing it yet. |
| tuxchick Sep 24, 2010 6:41 PM EDT |
bigg, ZaReason works directly with hardware manufacturers, and they never use non-standard parts. Anything can be replaced off-the-shelf. Scammy stunts like Dell pulls are really annoying-- all they do to their power supplies is change the pinouts. Yeah thanks Dell. Gateway used to get these under-sized PSUs that would not fit in a standard case. Another gotcha is onboard anything that relies on Windows drivers, like video and sound. These are pretty rare anymore, but you can still get stung sometimes. |
| Bob_Robertson Sep 25, 2010 1:04 PM EDT |
I've been compiling kernels recently, for kicks, and if someone could just point to where the "preemption" option is, I'd be thankful. |
| gus3 Sep 25, 2010 1:28 PM EDT |
@Bob: Under "Processor type and features", look for "Preemption model". There will be 3 choices: --No Forced Preemption (Server) --Voluntary Kernel Preemption (Desktop) --Preemptible Kernel (Low-Latency Desktop) The RT patch adds a fourth: --Complete Preemption (Real-Time) |
| Bob_Robertson Sep 26, 2010 7:20 PM EDT |
Fascinating. I found it, thanks, and I'm trying both "preemptible" and encrypted LVM. The compile of 2.6.35.5 took only a smidgen longer with the LVM than it did without it, so there doesn't seem to be excessive overhead. I wonder why the RT patch is still a patch. |
| gus3 Sep 26, 2010 9:50 PM EDT |
Well, as I understand it, Linus wants the current maintainers of the RT patch to be its permanent maintainers. However, without jumping through some hoops, the RT patch is incompatible with the NVidia proprietary driver, thanks to a semaphore rename. |
| tuxchick Sep 26, 2010 10:32 PM EDT |
The RT patch isn't strictly necessary for audio production, and you may not want it for non-audio work. The idea is to give audio processes the highest CPU interrupt priority, so once started they run until completed and do not get interrupted. With a high clock speed multi-core CPU, a good clean system that is not all bogged down with special effects and unnecessary services, and a well-performing audio chain you can probably do without an RT kernel. People get all excited about latency in audio production, but there are only a few circumstances where it matters: Overdubbing, monitoring while recording, and synchronizing diverse recording sources. If you're recording a band, for example, and they're all plugged into the same mixer (without any detours through outboard devices like special effects boxes) which is plugged into your computer, you don't need to worry about latency. |
| tracyanne Sep 27, 2010 12:35 AM EDT |
Quoting:Overdubbing, monitoring while recording, and synchronizing diverse recording sources. Those are exactly the sorts of thing I do, and with the default kernel it really is a bitch. I find the pre-emptive kernel works really well, though. At least on my multi core CPU. |
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