witch factor will really affect the latency???

[preachers]

cpu speed? RAM bus speed?? hard drive???

i want a excetly explain for it, i'm doing computer testing for SAC recently, and i'm wondering it

[sebastiandybing]

In my experience the audio card driver seems to affect the low latency most, both RME and Sydec run smoothly at 1/64 and RME run god at 1/32.

The next thing is the motherboard. My test show me that Intel perform best for audio at low latency, there is no audio interrups doing sreen redraw. where asus and another one I tested once in a while made sawstudio stop or made small interrups in the audio stream.

Sebastian

[preachers]

what about fireface 800? is there anybody used to test this card? i have two of this, but it not response a good result in my macbook pro, in my expirence, i have to set SAC to 1x128, with 28 channels when used a FOH and a Monitor 1 mixer. *x96 can't be accept, it will perduce some glitchs.but at my imac or pc dual core 2 it will get better, at that case, i can set SAC to 1x64 without problem.

who can give me a opinion about ff800, is it better or worse than other pci cards by RME???

[AudioAstronomer]

what about fireface 800? is there anybody used to test this card? i have two of this, but it not response a good result in my macbook pro, in my expirence, i have to set SAC to 1x128, with 28 channels when used a FOH and a Monitor 1 mixer. *x96 can't be accept, it will perduce some glitchs.but at my imac or pc dual core 2 it will get better, at that case, i can set SAC to 1x64 without problem.

who can give me a opinion about ff800, is it better or worse than other pci cards by RME???

FF800 should do just fine at 1x64

Follow this information here: http://www.gearslutz.com/board/music-computers/348951-howto-low-dpc-latencies-100-us-bootcamped-macbooks-pro.html

That will help you get the latency you're looking for on your macbook pro with SAC and the ff800.

Good luck!

[IraSeigel]

FF800 should do just fine at 1x64

Follow this information here: http://www.gearslutz.com/board/music-computers/348951-howto-low-dpc-latencies-100-us-bootcamped-macbooks-pro.html

That will help you get the latency you're looking for on your macbook pro with SAC and the ff800.

Good luck!

I haven't gotten my FF800 or FF400 down that low. And I understand from Bob's and others' comments in another thread that with FW, you're not likely to. PCI or PCIe (or CardBus?) is much better for lowest latencies.

PLEASE correct me if I'm mistaken.

Ira

[DominicPerry]

Ira,

Robert's using a MacBook of some sort to get these figures. The point about using a PCMCIA card rather than FW is partly around latency and partly around CPU load. It may be possible to get a FF800 to run at 1x48 but at what CPU cost? And each channel it is using will increase the CPU load. RME's PCMCIA cards don't work in the same way and so add no CPU overhead. And physically, they are a lot tougher connections on a PC (remember the MacBooks have a 'proper' 6 pin Firewire connection where most PC laptops have a fiddly small 4 pin one).

Dominic

[IraSeigel]

Ira,

Robert's using a MacBook of some sort to get these figures. The point about using a PCMCIA card rather than FW is partly around latency and partly around CPU load. It may be possible to get a FF800 to run at 1x48 but at what CPU cost? And each channel it is using will increase the CPU load. RME's PCMCIA cards don't work in the same way and so add no CPU overhead. And physically, they are a lot tougher connections on a PC (remember the MacBooks have a 'proper' 6 pin Firewire connection where most PC laptops have a fiddly small 4 pin one).

Dominic

So Digiface/CardBus (RME's adapter) is a better bet on a laptop than a FF800. I gather. ?

Well, I'm happy with my FF800 and not quite the lowest latencies, but darn good.

Ira

[DominicPerry]

So Digiface/CardBus (RME's adapter) is a better bet on a laptop than a FF800. I gather. ?

Well, I'm happy with my FF800 and not quite the lowest latencies, but darn good.

Ira

The Fireface has a latency setting of 48 samples. But it also has a 32 sample internal buffer which you can't avoid. So the minimum buffer size is actually 80 samples. The Cardbus card used to have a lowest buffer size of 64, but the PCExpress cards have a 32 sample buffer and the earlier ones may also have that too in the latest drivers. There are no guarantees that the Cardbus cards will be better, but generally they are easier to get lower latencies which are stable. You don't have to fiddle with FW patches, and when you get a low latency for one channel, it will act the same at 24 channels, whereas the Firewire solutions tend to need longer buffers as you load them up, because the bus is carrying more data - the Digiface effectively carries all 24 channels even if you are only using one, so what you get is what you get. I wouldn't change the Fireface unless you are having problems, but if you had a choice and owned neither, I would recommend the Cardbus/Digiface solution.

Dominic

[IraSeigel]

The Fireface has a latency setting of 48 samples. But it also has a 32 sample internal buffer which you can't avoid. So the minimum buffer size is actually 80 samples. The Cardbus card used to have a lowest buffer size of 64, but the PCExpress cards have a 32 sample buffer and the earlier ones may also have that too in the latest drivers. There are no guarantees that the Cardbus cards will be better, but generally they are easier to get lower latencies which are stable. You don't have to fiddle with FW patches, and when you get a low latency for one channel, it will act the same at 24 channels, whereas the Firewire solutions tend to need longer buffers as you load them up, because the bus is carrying more data - the Digiface effectively carries all 24 channels even if you are only using one, so what you get is what you get. I wouldn't change the Fireface unless you are having problems, but if you had a choice and owned neither, I would recommend the Cardbus/Digiface solution.

Dominic

Thanks, Dominic.

So what does RME mean when they claim "Zero Latency Monitoring"? Is that possible, given the intrinsic latency of the gear?

[DominicPerry]

Thanks, Dominic.

So what does RME mean when they claim "Zero Latency Monitoring"? Is that possible, given the intrinsic latency of the gear?

It's zero latency if you use TotalMix to route input to output without doing it through the DAW. RME have an article on their site about what digital-zero-latency really means. In short, you get a bit for A-D, some processing and then D-A. It's not much (sub 1ms), but it's something. If you want to be irritated by it, you can compare TotalMix foldback with an analogue path in headphones.

Dominic

[Bob L]

The zero latency monitoring is thru their hardware... and TotalMix... the signal is essentially a straight split of the original data in hardware... but that means it does not pass thru the application virtual mixer and all of its processing, like eq, comps and reverb... so in the case of SAC, you loose the ability and power of the 24 separate monitor consoles, and actually the FOH console as well... so it really is not a very useful conversation as far as SAC is concerned. :)

Bob L

[Iain Westland]

The Witch Factor usually only effects the latency around Halloween, or all year long in Salem, Mass.

been patting myself on the back for not making that shot and then you go and do it. Bang goes my thunder:D:D

[preachers]

thanks everyone that posted above, for several days research and test, it works fine now. mainly, according to AudioAstronomer's link, i simply disabled the kbdmgr.exe***12289;wireless netcard and touchpad program.
i get the 1x64 and it's stable now~~~

thanks everyone here again!!!!!

and a thing still there, i found it from RME's forum, winxp sp2 will reduce 1394 perfomence, and there're 2 patches released by Microsoft, but it needs to verify your copyright of XP before download it. i'm using a paricy version now, who can give some ideas to get them?

[jazzboxmaker]

"who can give some ideas to get them?"

M'lad, sure as you'll be visiting Davy Jone's Locker with that kinda talk;)

[DominicPerry]

thanks everyone here again!!!!!

and a thing still there, i found it from RME's forum, winxp sp2 will reduce 1394 perfomence, and there're 2 patches released by Microsoft, but it needs to verify your copyright of XP before download it. i'm using a paricy version now, who can give some ideas to get them?

You're welcome to the help.
We don't do piracy round here. But you can find a fix if you are using XP SP2 by replacing some of the driver files with versions from SP1 and making a registry fix.
Look here for the driver information
http://www.rme-audio.de/en_support_techinfo.php?page=content/support/en_support_techinfo_firewire_xp
under the section : Back to SP1
Search the forums under SidSpeed to find my posts which explain what to do for the registry fix.

Dominic