Mac Pro 2008 with HD native and Omni buffer question.

[lancemcv]

Hi, I just got my native system pcie card PT10HD and Omni interface and have updated to the latest firmware for both the card and Omni without issue. It seems I cannot set the buffer below 128 without
getting errors saying to increase the buffer. I guess my Mac Pro with 16 gigs of ram just can't handle the lower buffer settings. Does any one have the same setup and are able to use the lower buffers. This is just with one track and nothing else 44.1 24 bit recording on an interenal SATA drive that is for audio only.
At 128 and 256 all seems pretty solid, but at 32 I can hear the Omni cutting in and out in my headphones and if I hit record I get the error to increase the buffer. I have two video cards installed in my Mac Pro and my Native card is installed in the third slot which is a 4X as is the native card.
Would there be a benefit of installing it in the faster slot 2. Somehow I doubt it.
Any feedback with someone with the same setup would be appreciated.
I know a faster mac would help the buffer settings so I hope new mac pros come out this year.

[lancemcv]

After playing around with the hardware setup, switching between the Omni and my MBox Pro things have improved with the omni some or omni native combo. I was able to leave the buffer set to 32 and not have it dropping in and out. I also no longer get a message at launch of pro tools that I was getting about the Mbox Midi is not available. So perhaps there was a bit of a glitch somewhere where Pro tools was still looking for the mbox in the background because of the midi warning. So I actually recorded a bit at 32 buffer and even though it did not last too long without getting an error at about 1 minute it seems happier than before.
I am used to leaving my buffer at 512 for mixing and higher which is all I do at my place unless I record the od vocal or guitar overdub. So just testing it's limits with my mac pro.

[Markk]

Kept us posted

[lancemcv]

It seems 32 and 64 buffer settings on my Mac Pro 2008 are not usable, at 128 things are pretty good, 256 is rock solid. I have 2 video cards installed, the native card and one open slot. I have found with native systems MBox pro especially if you have two many things connected that draw power like a two bus powered usb drives off a USB hub you will start getting more errors, and I was not recording on them they were just connected. Yesterday I tried doing an overdub using my macbook pro to screen share my Mac Pro so I could remote control pro tools but it really messed with pro tools and was constantly disconnecting and spitting out errors. I turned it off and pro tools was back to normal. I guess screen sharing taxes the CPU quite a bit. I am going to pull my second video card that is powered by the pcie slot and remove all other peripherals and see if I can get a lower buffer setting to work without errors.

[Drew Mazurek]

My single 2.8 Harpertown can do 32 (barely) and 64 (comfortably) for tracking sessions with my Native card and HD I/O 16x16.

[lancemcv]

What card slot do you have your native card installed in?

[Drew Mazurek]

Originally Posted by lancemcv

What card slot do you have your native card installed in?

Not sure, would have to check. I'm at another studio today.

I also have a UAD Quad and an Octo in this computer so all slots are filled.

[lancemcv]

ok thanks

[lancemcv]

Okay so I ran some more tests and when I set my CPU all the way down to one core I can then recorded at 32 buffer even 48 tracks for about 4 minutes before I get an error. When I bump the cores up to 7 out of 8 the audio cuts in and out and I can't record at all. My Macbook pro 2012 can record at a buffer of 32 without errors and that is with the exact same system as it is a clone of my Mac Pros system so it is not a system issue. If I am at 128 or 256 on the Mac Pro I have no errors so I guess it's just the chip set of the 2008 Mac Pro is pretty unstable at low buffer settings.