First Cracking Rig

[FrostByte]

I'm doing some research on building my first cracking rig with 8 x GTX 1080s and could use some advice. From what I gathered so far, cracking rigs can't be built with the same specs as mining rigs as CPU/RAM/Disk IO actually matter.

I'm considering getting this chassis for portability, since I might need to move it to cooler rooms in the house - https://www.amazon.com/Hydra-III-Server-...861&sr=8-4

Then slapping in a standard ATX like this -- https://www.amazon.com/gp/product/B01N2R...518a83adbc

Along with 32 GB of RAM, a decent CPU, two 1600 PSUs with PSU splitter connected to the mobo, and SSD.

Is there anything I should know before going this route? Other considerations? Any advice would be great.

[royce]

I hadn't seen that case before - interesting form factor. If you intend to run long jobs, make sure that your cooling of the room itself is adequate.

I haven't done the math, but 2x1600 PSUs seems a little high for 8x 1080s. But it might be buying you some future-proofing (if you upgrade the cards someday), so that may be fine.

What will be using to connect the cards to the board? I haven't looked around for M.2 risers.

Eventually, most crackers get to the point where they wish they had more RAM (for sorting large wordlists). I try to max out the RAM.

[FrostByte]

I hadn't seen that case before - interesting form factor. If you intend to run long jobs, make sure that your cooling of the room itself is adequate.

I haven't done the math, but 2x1600 PSUs seems a little high for 8x 1080s. But it might be buying you some future-proofing (if you upgrade the cards someday), so that may be fine.

What will be using to connect the cards to the board? I haven't looked around for M.2 risers.

Eventually, most crackers get to the point where they wish they had more RAM (for sorting large wordlists). I try to max out the RAM.

Yeah, the portability with the handles is what I like most. The rig will be in my office most of the time, but it can get hot in here so being able to just move it downstairs is a huge plus for me. Network connectivity will be by a USB wireless card. Two 1600 PSUs is probably overkill but like you said, it does add some future-proofing and a decent buffer. 

I haven't looked at M.2 to PCIe risers either, but that's the goal is to have risers for all the onboard PCIe slots, then M.2. to PCIe adapters for the two M.2. slots on that motherboard. I'll do some more research but I've read miners often do that since finding a mobo with 8 PCIe slots is a bit rare.

Good call on the RAM, I'll probably push it to 64 GB then.

[royce]

Since mining has dropped off a bit, you can probably pick up some of the higher-end multi-PCIe boards for pretty cheap. Some examples:

http://bitcoin.zorinaq.com/many_pcie/

Some attacks are happier with more PCIe lane bandwidth.

[FrostByte]

Since mining has dropped off a bit, you can probably pick up some of the higher-end multi-PCIe boards for pretty cheap. Some examples:

http://bitcoin.zorinaq.com/many_pcie/

Some attacks are happier with more PCIe lane bandwidth.

I thought the GPUs are going to run at PCIe x1 speed though regardless?

[undeath]

certainly depends on how many pcie lanes your board/cpu(s) have

[FrostByte]

certainly depends on how many pcie lanes your board/cpu(s) have

Interesting. I haven't thought about that. Is there a huge difference in terms of cracking speed with more PCIe lanes? It'll primary be for cracking NETNTLMv2, NTLM, WPA, and Kerberos TGS.

[undeath]

depends on the attacks you run. For wordlist attacks (a0) with no or few rules your bandwidth will limit the cards. With those cards you might even see a bottleneck with slower algorithms such as WPA in such a case.

[FrostByte]

depends on the attacks you run. For wordlist attacks (a0) with no or few rules your bandwidth will limit the cards. With those cards you might even see a bottleneck with slower algorithms such as WPA in such a case.

Do you have any recommendations for a good mobo/cpu combo?

[NoReply]

If you can afford it, going with a threadripper is a good idea imo, since the smallest one (1900X) is available for a decent price ( ~ 280 € in my country) and they boast 64 PCIe lanes, which is more than a workstation Xeon has. Drawback is that the boards are quite pricy and there are very few to choose from.

From doing a quick lookup I would say a Gigabyte Aorus Pro AMD X399 (https://www.gigabyte.com/Motherboard/X39...PRO-rev-10) has enough connectivity for 8 cards, but it is necessary to check the details (e.g. does every m.2 slot connect to the PCIe interface, or is it SATA only).

Another plus is that you have 8 RAM slots, which scales well. Also here in the forum it is recommended to have RAM >= VRAM to prevent CL_OUT_OF_RESSOURCES errors.