Archive for May, 2011

Just thoughts

Currently,  the onyl advantage of gaming consoles is huge cpu-gpu interconnect bandwidth:

PS3:  Cell FlexIO bus interface
20 GB/s read to the Cell and XDR memory
15 GB/s write to the Cell and XDR memory

XBOX360: 21.6 GB/s front side bus

10.8 GB/s upstream and downstream

it looks huge (especially ps3)  in comparision with pci-express 2.0 x16

which is 8GB/s upstream and 8GB/s downstream. It isn’t bottleneck in current game’s developing paradigm because it was created to workaround that bottleneck in ages of pci-e 1.1 or even agp. Just compare 2gb of vram on 6970 and 256mb vram on ps3. Cell cpu in ps3 can quickly feed gpu with needed data without the need to store everything in vram to keep up with fps. On pc, for sake of speed you gonna store as much as possible in gpu’s vram. (Yeah, I understand the difference in the output resolution, but still..)

But, next generation of pc gonna fix that, there is already a lot of pci-e 3.0 mainboards you can see on computex these days. Its gonna be released when sandybridge-E and ivybridge will be launched.

Pci-e 3.0 gonna give us 16 GB/s downstream and 16 GB/s upstream, which is now comparable to ps3.

I just wonder what game developers can do if they will not care about backward compatibility and will fully use that 32 GB/s (total bandwidth) line.

ATY_Init for 6870.

Tested it myself. what works:

  • minidp ports, active and passive adapters
  • hdmi port
  • upper dvi port
  • dvdplayer/geekbench/steam

what doesnt work:

  • second dvi port
  • dvi->vga adapter on upper dvi port, for vga displays you will need active mdp->vga


  • dl-dvi on upper dvi port, dl-dvi should work via apple’s minidp->dl-dvi adapter tho, the adapter was tested to work, dl-dvi wasn’t

To install it you need this ATY_Init and ati drivers from 10.6.7 update for newest imacs.

MacPro users – this will not work, for macpro bios of 6870 need to be embeded into Info.plist of aty_init.

To use with Lion,  install framebuffer (atiframebuffer, atisupport, ati6000controller kexts) from that imac update.

Enabling OpenCL for Fermi GF100 cards for Lion

Latest Lion update (as well as previous one) disables opencl functionality for gtx480/gtx470.

Looks like it was made intentionally, because you can enable it changing just two bytes in GL driver :D , one for 32-bit part and one for 64-bit part.

You need to patch this file: /System/Library/Extensions/GeForceGLDriver.bundle/Contents/MacOS/GeForceGLDriver


a8 83 f8 02 8b 45 f0

replace 02 with 03 to get

a8 83 f8 03 8b 45 f0


ea 83 f8 02 49 8b

replace 02 with 03 to get

ea 83 f8 03 49 8b

11a459e and 10k521

first, new Lion build, has a bit newer nvidia drivers – 7.0.82 270.05.00a08

still no gtx580/570 dev-ids in it

ati x3000 kext version – 7.0.82 9749 (previous update – 7.0.75 9698)

10.6.8 beta – no fermi drivers at all

ati x3000 kext version – (9707) (from latest imac update –, so not much newer

anyone wanna test 6970 ?

P.S. imac’s update as well as 10.6.8 beta has sandy bridge video drivers.

Report of hybrid gpu system

I’ve tested today a system with one nvidia (8800gt) and one ati (4850) card and how this combination behaves in osx and win7.

win drivers – catalyst 11.4 and geforce 270.xx
osx drivers – from latest imac update.

first variant: nvidia – first card (POSTed by bios), ati – second
win7: gpu-z cant show proper info about ati card until I plug a display connector to it, then I still cant use 3d renderer of ati card, only 8800gt renderer available to opengl apps. Aida64 says only one d3d/opengl renderer available. this combo leads to a lot of instabilities of Win7. I cant run any directcompute/opencl app on 4850, system freezes.

MacOSX Snow Leopard: All works fine. Can use both renderers (8800gt and 4850) with any screen combination (for example app rendering on 4850 can be shown on screen driven by 8800gt, this leads to some fps drops, cuz system needs to copy rendered image from one card to another, but fps still at acceptable level). Can use opencl engine of any card at any time, and both in time. No problems except one – when running luxmark using both opencl devices (it cant use jsut one), the gui is very slow.

second: 4850 is first card, 8800gt is second.

Win7: even more freezes, durring running gpuz.
OSX: 8800gt wasn’t initialized by drivers, so drivers doesnt see any outputs on it, any renderers/opencl devices. 4850 works fine.

First ati 6xxx FrameBuffer Names

6770m – Hydrilla
6970m – Elodea
6970/6950 – Gibba


Upgrading 2009 MacPro to 2010 MacPro

A user of our forum has released an app to upgrade 2009 MacPro with firmware of 2010 MacPro, allowing 2009 MacPro to support hex-core cpus.
It also allows downgrade back to 2009 MP’s fw.

You can find it here

The app has no Apple’s code inside and does all manipulations with fw files on your computer.

Got new iMac?

If you got 2011 imac with 6750/6770/6970 M card and has windows installed, can you dump your video bios with gpu-z, upload and post in comments ?

Just funny numbers

Nvidia’s dual-gpu cards power consumption:


Try to guess what will be next.

OHAI GF110 and OpenCL for Fermi

Go grab 10.6.7 update for new imacs here and update for new mbps here (drivers are same, mbp update is smaller), extract all GeForce* and NVDA* kexts/bundles from /System/Library/Extensions folder and install them.

NVDAGF100Hal (256.02.05f01)

0x108010de&0xffe0ffff <– GTX580, GTX570

This update brings opencl support for fermi to Snow Leopard and breaks cuda :D

To get CUDA back, execute this command in terminal:

cp /Library/Frameworks/CUDA.framework/Versions/A/Libraries/libcuda_256.01.10.dylib /Library/Frameworks/CUDA.framework/Versions/A/Libraries/libcuda_256.02.05.dylib

[Device 0]
Name: GeForce GTX 480
Vendor: NVIDIA
Type: GPU
Device Version: OpenCL 1.0
Driver Version: CLH 1.0
Compute Units: 60

it also has updated ATI drivers, anyone wanna test 6970 ?

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