NVIDIA GeForce GT 120 in new Mac Pros Looking for technical details

i just got an iMac (early 2009) with the GT130. here is the output of deviceQuery:

Device 0: "GeForce 9600 GT"

  Major revision number:						 1

  Minor revision number:						 1

  Total amount of global memory:				 536543232 bytes

  Number of multiprocessors:					 8

  Number of cores:							   64

  Total amount of constant memory:			   65536 bytes

  Total amount of shared memory per block:	   16384 bytes

  Total number of registers available per block: 8192

  Warp size:									 32

  Maximum number of threads per block:		   512

  Maximum sizes of each dimension of a block:	512 x 512 x 64

  Maximum sizes of each dimension of a grid:	 65535 x 65535 x 1

  Maximum memory pitch:						  262144 bytes

  Texture alignment:							 256 bytes

  Clock rate:									0.34 GHz

  Concurrent copy and execution:				 Yes


just as an info, if someone is interested into it…


Unfortunately, this is almost certainly the power-saving clock rate.

tmurray, can we please have a field in the device properties data structure for “max clock rate” so we know how fast the GPU will be when CUDA starts using it? These fancy dynamic clock rates are confusing. :)

I have some new experience with NVIDIA cards in 08 model Mac Pros that you might find helpful. it is all documented at:


The replacement of the 8800 by the 120 aside, I have managed to get an 8800 PLUS either a GTX 260 OR a pre-production TESLA working under Windows XP on Bootcamp, so that two GPUs are recognized. I strongly suspect this will apply to 09 model. OS X 10.5 does not recognize the 260 either as graphics or CUDA, though it is very happy with the 8800 on both counts.

using the latest SDK and Toolkit the Clock rate is:

Clock rate:									1.30 GHz

My disappointment about the level of computation in the 120 has just eased somewhat. On rummaging round the various specs for the 09 'Pros it looks like

(i) the 120 uses NO auxiliary PCI-E power cables (95% certain now - can someone confirm?)
(ii) the optional Radeon uses two PCI-E power cables, and there are two on board connectors as with the 08 Pro.

What this suggests is that if the necessary drivers (and EFI stuff) get sorted out for OS X, you could put the 120 in one of the slots and have a 260, 280 or 285 or Tesla in another and run it off the supplied power connnectors with a closed box, no jerry-rigging off external PSUs or other power connecters etc. This ought to work under Bootcamp right away.

So the minor problem I have with my 08 Pro, which is that a combination of 8800+260 needs three PCI power connectors (and for now an external ATX supply and an open box with cables everywhere.) would go away - I have not figured out how to power the 260 off a disk or optical power line). In the 08 Mac Pro it is only the ATi card that runs without extra power.

If anyone has an 09 Pro with the 120 and a spare GTX card (not the 295 sadly) perhaps they could see if this is right? Bootcamp windows could also run with one set of NVIDIA drivers.

Most video cards I’ve bought have come with adapters to convert two 4-pin molex connectors to a 6-pin PCI-Express power connector. (My 8800 GTX cards even came with two.) Unfortunately, the 4-pin connector is really only used for IDE devices and after-market case fans, and so I would imagine that Apple has already dropped it from their Mac Pro.

Another option would be to stick a supplementary power supply in there:


That model provides two 6-pin PCI-e connectors. However, this also might not work if the Mac Pro does not have any 5.25" bays.

Indeed - my GTX 260 tryout came with a supply of those 4-pin molex adapters - but I could not find anywhere openly accessible to plug them in. Plan B is to buy a cheap PC NVIDIA card not needing a pci power cable and see if I can flash it to replace the 8800GT, then feed the 260 with the two available cables! I would very much like to know if the 120 can work in an 08 Mac pro for the same reason.