OTOY Forums

Hi, DO,

That amfeltec chanel thing is wheather host card allows You to plug one, two or four clusters from one host card- as You want need only 2 or 3 GPU single chanel host card is enough =)

As for animation there's abit of a difference depending on what you do =) let's look this way.. If Your scenes are prety simple & thus light enough based on transfering data, but the render time is longer - than 1x is more than enough. The problem is if You'r using really complex scenes that has alot of data to move & simple renderin algorithms (like direct lighting) for fast output - do You get what i would like to say? Based on your workflow needs You can feel bigger or smaller influence of that upload speed, but for some it's completelly fine =)

I'd say it's not a bad solution to try out, at worst You can try to sell it if it will not fit Your needs =) there's quite a demand for those units as GPU render engines gain popularity =) so I do't think that would be a problem =)

Hope that helps =)

Thanks Tom,

Single channel it is .. I'm sure I won't be going over 3 additional GPU on this setup.

More worried now that Amfeltec said it may not work on a 2009 mac pro ... not sure yet why. I'm probably crossing over to the PC world next year but was figuring this was a short term solution.

Yep, totally get what you mean on the animation load time. My complex Octane scenes are usually "camera only" animation (architectural) so it's a single frame hit (and a longer wait for LV to load/update) ... but my rendering tends to be long (even in DL) due to diffuse depth, materials, samples, frame size (1080), etc. so probably less of an issue than if I was doing full on character or dense mograph.

Thanks for the help.

Just got this from Amfeltec sales:

I am not so familiar with Mac but I know that at the beginning of the PCI Express on some computers BIOS had a problem to operate with PCI Express switch (it can’t support more devices than numbers of PCI/PCI express slots on the motherboard).

Nothing special regarding Mac 2009.

If anyone is familiar with this ... would realllly appreciate any comment on whether this is an issue for mac pro's.

Edit: Just saw a thread on macrumors that seems to go into this in more detail and suggests OSX may have a limit of 4 GPU's ... will jump to that thread but thanks for all the advice!
http://forums.macrumors.com/showthread.php?t=1842150

DigitalOven wrote:Just got this from Amfeltec sales:

I am not so familiar with Mac but I know that at the beginning of the PCI Express on some computers BIOS had a problem to operate with PCI Express switch (it can’t support more devices than numbers of PCI/PCI express slots on the motherboard).

Nothing special regarding Mac 2009.

If anyone is familiar with this ... would realllly appreciate any comment on whether this is an issue for mac pro's.

form new thread with very specific topic, like "2009 MacPro maximum number of cards" or "who have 2009 MAC with multiple cards"- something along those lines. I've heard Guys using 2-3 cards without problems, but I'm not sure 'bout anything more..

Think Terry (aka Tuttor) has some Macs - You can try to drop a line for him directly =)

glimpse wrote:

DigitalOven wrote:Just got this from Amfeltec sales:

I am not so familiar with Mac but I know that at the beginning of the PCI Express on some computers BIOS had a problem to operate with PCI Express switch (it can’t support more devices than numbers of PCI/PCI express slots on the motherboard).

Nothing special regarding Mac 2009.

If anyone is familiar with this ... would realllly appreciate any comment on whether this is an issue for mac pro's.

form new thread with very specific topic, like "2009 MacPro maximum number of cards" or "who have 2009 MAC with multiple cards"- something along those lines. I've heard Guys using 2-3 cards without problems, but I'm not sure 'bout anything more..

Think Terry (aka Tuttor) has some Macs - You can try to drop a line for him directly =)

MacPro 2007-2013s have four PCIe slots, only one of which Apple intended to be used by a double width PCIe card (slot 1 - note the spacing); the others are single width slots. OS and IO space limitations on MacPro 2007-2013s allow for use of up to 4 GPU processors, although some have reached 5 GPU processors, but most of them have stability issues. For other types of PCIe cards, the working card count is higher. There are external chassis for the MacPro that have four (or more) double wide PCIe chassis, but the majority of the people that I've heard about who have those type chassis, seem to hit a brick wall after 4 GPU processors total for the entire system (MacPro and external chassis combined), and only a tiny few have reached 5 GPU processors. Put in six however spread between the MacPro and the external chassis, and the system will not boot and with five, the vast majority of those will not boot.

Only the old MacPros are fully capable of having internal Nvidia GPUs. I have four of them. The most significant thing to have happened to the MacPro line when it comes to running CUDA cards was Nvidia's introduction of the GTX 680 Mac Edition. That, along with Nvidia's recognition that there are still lots of Pre-2013 (the cylinder) MacPros in the wild, accounts for the driver updates. Over time, this will end, unless something radically changes at Apple. I now buy for the future and the future of GPU rendering is Windows and Linux, not MacOS.

The pic below shows some info about one of my four MacPros (it's the 2007 version) that was then running 2xGTX590s (each dual GPU processor cards); I tried installing one of my GT640s, in addition to the two 590s, and the system wouldn't boot. I tried installing other cards also with the same result. So that why I used the term "GPU processors" instead of "GPU cards" because if the cards are dual GPU processor cards, then the limit is 2. But you can install up to three double wide CUDA cards (single GPU processor version) in a Pre-2013 MacPro's case along as you adequately power it [ http://forums.macrumors.com/showthread. ... st18872245 ]. The saving grace is that as future GPU processors become more powerful, the three double wide CUDA (single GPU processor) card installation limit for inside of the MacPro's case, will not matter as much.

Love this forum (& it's user base), so much cool info here! =)

DigitalOven wrote:Just got this from Amfeltec sales:

I am not so familiar with Mac but I know that at the beginning of the PCI Express on some computers BIOS had a problem to operate with PCI Express switch (it can’t support more devices than numbers of PCI/PCI express slots on the motherboard).

Nothing special regarding Mac 2009.

If anyone is familiar with this ... would realllly appreciate any comment on whether this is an issue for mac pro's.

Edit: Just saw a thread on macrumors that seems to go into this in more detail and suggests OSX may have a limit of 4 GPU's ... will jump to that thread but thanks for all the advice!
http://forums.macrumors.com/showthread.php?t=1842150

MVC's pic, shown in the thread that you've referenced, displays only 4 GPU cards (and 5 GPU processors) for his new eGPU device, because each GPU processor of the Titan Z, just like the GTX 590 in the pic that I've displayed, shows as two cards in the "About This Mac" window [ [ http://forums.macrumors.com/attachment. ... 1422527711 ] ]. So it is really running just one Titan Z (a dual processor card), a GTX 780, and with regard to the AMD processors (showing as "AMD Fire Pro D300"), there may be two additional cards, at best*/. If you look closely at MVC's pic of the Octane window [ http://forums.macrumors.com/attachment. ... 1422527711 ], you see (on the mid right side that only three GPU processors are recognized (2 for the Titan; 1 for the 780) and none for the AMD(s) (not supported).

*/ I said "at best" because those cards aren't sold as "AMD Fire Pro D300;" so I'm not sure what card(s) that/those really is/are.

P.S. Given MVC's EFI skills, if the IO space of a card can be modified, it doesn't surprise me that MVC would be the one to do it. After all, his nic is "MacVideoCards" and he keeps earning it daily.

Wow, thanks for the great information, really helping me figure this out (bold new worlds). So many threads and trying to read through all of them can be a little confusing at times. (again, sorry for hijacking this one).

Also thanks Tutor for the link to your setup with 3 GPUs in mac pro ... could be best solution for me at the moment rather than external cage.

agree with Glimpse ... great forum!