OpenCL machine..

[NickK]

Perhaps a cheap NV card and a cobbled-together Linux system in the meantime? Or one of those external laptop GPUs?

http://www.pcworld.com/article/2839...you-add-a-desktop-video-card-to-a-laptop.html

needing up to 375 watts of electrical power

Hmm the 8GB graphics cards are indicating a minimum of 650W. Nice idea though.

Not sure when Apple's next hardware refresh is - the annoying bit is an 8GB GPU linux box, even with duff drivers, is likely to return performance better than the MBP.. but without being quite as portable.

On the astronomy side of things - I've been using a mac mini and screensharing but that's not ideal due to the slow frame rate. The portable element may result in me going for another MBP with an average GPU again. It means I get to support OS X and Linux from the same machine.

 

[MagicBoy]

Hmm interesting.. how did you get a replacement? My system log and I have images of the GPU hangs available to back my statement up.

Thread here : http://forums.overclockers.co.uk/showthread.php?t=18596137

Not sure when Apple's next hardware refresh is - the annoying bit is an 8GB GPU linux box, even with duff drivers, is likely to return performance better than the MBP.. but without being quite as portable.

rMBP refresh in the second half of the year I expect. They'll be waiting on Broadwell-H. As to it being nVidia or AMD - dunno. AMD are back in favour for the desktops.

 

[pete910]

Amd's Linux support is dire, and has been for the last 20 years since I have been using Linux (and likely terrible for many years before that!).

I call BS on that!!!

Please post references/forum links to a 20 year old AMD gpu where the user is having problems.


Or are you just following the crowd?

Btw, I will concede OpenGL performance is bad on AMD GPU's in *nix with the 290's. The hd5xxx however drivers were excellent. But to say their dire for 20 years ain't really fair and just plain wrong.
Also Opencl performance was way ahead of Nvidia's up until the release of their GTX9x family of cards. That's on consumer based cards, What the workstation cards are like compared to each other I have no idea.

 

[joeyjojo]

My second MBP 15" has the doom Radeon 6750M .. it's GPU is failing with hangs etc.

The 6750M has peak 576 GFLOPS. Is that enough power? Because even the Intel 5000 (GT3) has 704 GFLOPS, bumped up to 832 for the Iris Pro 51/5200 (GT3/e). I can't imagine you'd have much trouble tuning for it over AMD/Nvidia GPUs.

All this assumed SP rather than DP.

If 700-830 GFLOPS is enough, and you value portability, I'd say go with the macbook.

Edit: or if saving money is a priority, you could go as low as an R7 250 (£66) with 806 GFLOPS SP, similar to the Intel offerings (with 1 GB GDDR5, if you really need 2 GB you've got to bump up to a 260/X, but they're substantially faster at 1536/1971 GFLOPS respectively).

 

[NickK]

The 6750M has peak 576 GFLOPS. Is that enough power? Because even the Intel 5000 (GT3) has 704 GFLOPS, bumped up to 832 for the Iris Pro 51/5200 (GT3/e). I can't imagine you'd have much trouble tuning for it over AMD/Nvidia GPUs.

All this assumed SP rather than DP.

If 700-830 GFLOPS is enough, and you value portability, I'd say go with the macbook.

Edit: or if saving money is a priority, you could go as low as an R7 250 (£66) with 806 GFLOPS SP, similar to the Intel offerings (with 1 GB GDDR5, if you really need 2 GB you've got to bump up to a 260/X, but they're substantially faster at 1536/1971 GFLOPS respectively).

Enough powah?!?! hehe - one thing to note here is that OpenGL GLFOPS often differs from OpenCL performance. nVidia's non-compute GPUs typically have disabled reduced processing for OpenCL vs OpenGL.

No - seriously, I can add more into the pipeline and make use of more GPU power and memory. The issue is that the more that is added the more memory is usually required. The MBP has 1GB so it's a good starting point as the mainstream machines have about that. Note with OpenCL you will typically get about 40% of memory max by default however it's possible to push that up but the OS will take a portion.

However I get your point - looking at the relative performance means any is really going to be a match for the 6750M...

The main issue normally is memory bandwidth - there's a massive requirement here as processing is usually doing, basically, 4K textures.

 

[CAT-THE-FIFTH]

The reason Apple is increasing going for AMD GPUs is due to their OpenCL performance and the fact that Adobe itself has moved over to mostly using OpenCL due to the urging of Apple. For CS,AFAIK there are now more officially supported AMD cards than Nvidia ones.

Edit!!

Having said that I would say that ATM Nvidia does have better Linux drivers than AMD,looking at the experience of some of my friends.

However,it might be worth seeing how well the Broadwell and Skylake GT3 and GT4 GPUs do though.

 

[CAT-THE-FIFTH]

I had an idea - why don't you first build the rest of the machine OP and get two equivalent AMD and Nvidia cards and try both with the software you are using. You can send the card you don't want back and pay any restocking costs. That way you will know definitely what is the better solution??

 

[NickK]

I had an idea - why don't you first build the rest of the machine OP and get two equivalent AMD and Nvidia cards and try both with the software you are using. You can send the card you don't want back and pay any restocking costs. That way you will know definitely what is the better solution??

That's a good idea!