06-29-2019, 06:09 PM
You're kind of all over the map here. You just went from 4x $105 GPUs to possibly 2x $700 GPUs or 3x $150 GPUs.
I think you need to:
1. Determine your budget, as this will always be the most impactful limitation,
2. Determine your goals are - what are you cracking, and what are you hoping to accomplish?
3. Do some research and look at some benchmarks. The K40 purchase shows you've not done any research on this topic, as if you had, you would have known to snag those M40s (which have performance similar to the Maxwell Titan X) instead of the K40s!
#1 & #3 combined will help you get the best bang for your buck. I highly recommend that you keep things simple, especially as a newcomer. There's virtually no reason to go for 3 or 4 low-end or mid-range GPUs if they'll be outperformed by one high-end GPU. One GPU will also be easier and cheaper to power, and easier to cool. If you can afford two or more high-end GPUs, that's awesome. But you'll need to do some research first, as it's not anywhere near as simple as "buy computer, buy GPUs, stuff GPUs into computer." The Hardware forum is chock-full of information on building a proper rig built to meet the demands of password cracking workloads, you just have to be willing to put in the work as no one here will spoon-feed you answers.
I think you need to:
1. Determine your budget, as this will always be the most impactful limitation,
2. Determine your goals are - what are you cracking, and what are you hoping to accomplish?
3. Do some research and look at some benchmarks. The K40 purchase shows you've not done any research on this topic, as if you had, you would have known to snag those M40s (which have performance similar to the Maxwell Titan X) instead of the K40s!
#1 & #3 combined will help you get the best bang for your buck. I highly recommend that you keep things simple, especially as a newcomer. There's virtually no reason to go for 3 or 4 low-end or mid-range GPUs if they'll be outperformed by one high-end GPU. One GPU will also be easier and cheaper to power, and easier to cool. If you can afford two or more high-end GPUs, that's awesome. But you'll need to do some research first, as it's not anywhere near as simple as "buy computer, buy GPUs, stuff GPUs into computer." The Hardware forum is chock-full of information on building a proper rig built to meet the demands of password cracking workloads, you just have to be willing to put in the work as no one here will spoon-feed you answers.