Nvidia CUDA or ATI Stream for MD5 encryption?

Question

I was just set to purchase a Nvidia GTX 470 when i saw some statistics regarding ATI which i didn't know.

Is stream on an ATI card much better at performing the maths required for encryption and decryption?

Answer 1

I have no horse in this race; but as someone trying to do my own GPGPU development and who knows a number of other people doing the same, let me observe:

1. Getting close to peak performance on the ATI cards is harder, because not only do you have to break the computation units up into the very many compute cores, you actually have to 4-way vectorize the calculation on each of the many cores. For something simple like encryption or MD5, this may be straightforward, but it's another step you have to go through.

2. The development tools (a debugger and a profiler, plus an entire online development community) that come for free with the NVidia SDK are way more useful than anything that comes with the ATI stuff. It's all well and good to say that OpenCL is OpenCL, but that won't help you find a sneaky bug or find out why your occupancy is lower than you think it should be. There are commercial third-party products out there that support the ATI stuff that may just be the most amazing tools ever made for all I know, but it will cost you.

Answer 2

I am doing AES on NVIDIA's GPUs and managed to achieve near 100% occupancy on 470. I have played with OpenCL for a while and it definitely is not something on which you can achieve performance. It's only benefit is it's wide acceptance and x86 support but if you're talking about getting performance, go for NVIDIA.

Note: If this is something you can outsource then send me an email: salman@tunacode.com

Answer 3

If the questions is not about CUDA vs openCL for MD5 hashing (since this would not be about cards but the api you use to implement the problem) then from what I ve seen though in cryptocurrency, ATI hardware is more suitable for hashing algorithms (openCL implementations)

If I am not mistaken, md5 hashing performance is the same as SHA-256 so you could just check the list of Hashing performance (Hashes/sec) of each card here:

Hashing gpu hardware comparison

Note that this is taken from litecoin, which is scrypt based hashing, but the max hashing power of each card is approximately the same, its just that hash algorithm that changes the difficulty of calculation.