Need spec assistance on a build

[kefka]

Hello,

This is my first post so I apologize if things I will be asking have been covered.

Goal: Build a machine that has Single MD5 speed of 60,000 M/s

Current Part List:
Motherboard = TYAN FT72B7015
CPU = 2 Intel Xeon 5600 series
RAM = Carsair Vengeance 1866 32GB
Hard Drive = Callisto Deluxe 240gb 280mb/270mb rw or Fusion-ioDrive2 400gb 1.4gb/1.3gb rw


The two expensive components are the motherboard and potentially the hard drive. I am trying to prevent any bottleneck in the system so I get max potential out the the video cards. I could get a much cheaper motherboard but most are not truly x16 in all the the PIC3 2.0 slots. If you more video cards in the tend to reduce the speed. For instance the Big Bang-Marshal (B3) on most sites says 8 x16 PCI slots but really its (2x16, 2x8, 4x1). I read that PCIe 2.0 has a bandwidth cap of 16 256gb a sec (16gb per channal *16). The video card specs for AMD HD 6990 says it has a 320gb/s memory bandwidth. So should I go with say a 5790 that has a 256gb bandwidth or am I just over analyzing and I can get with a cheap-o motherboard, hard drive and less expensive video card?

Any help is appriciated.

Cheers,

Kefka

[KT819GM]

For MD5 you don't need bus bandwidth as all work is done one video cards itself. On this forum there is even explanation why for hashcat pciex1 is more than enough. Don't be lazy and search a bit.

p.s. 1xHD6990 gets around 10G MD5 on oclHashcat-lite (not over clocked) so you will need as much as 4 of them to achieve speed you want by hardly over clocking them and it's max number of possible AMD gpu.

[kefka]

KT819GM - Thanks for a suggestions. So basically, unless I am going to double up and use this rig as a render farm as well it is PCIx1 all the way. I think I will save myself $2,500 on the mother board and by a fer of amfeltec 1 to 4 PCI express splitters!

kefka

[KT819GM]

Ive just told for your goal - so yes, you need only 4 pciex1 4 risers, 1 cheap motherboard with sempron like cpu, 2 gb ram, and 1 8 GB usb key for os install. All that will be price dependent - GPU's and PSU's. On psu you can save money by buying older one from server racks 1,5 or 2KW units at ±40 usd, but then you also will need some tech knowledge to attach it to your cards without burning them.

[forumhero]

also the limit of AMD driver is 8GPU per machine, so your goal of 60,000 M/s won't happen unless the soon to release HD 7990 can get 15,000 M/s per card.

[gat3way]

also the limit of AMD driver is 8GPU per machine, so your goal of 60,000 M/s won't happen unless the soon to release HD 7990 can get 15,000 M/s per card.

8x7970s should do about 65G/s

[atom]

If you overclock you can do it with 7.

[forumhero]

wow wtf i couldn't do basic math that day. haha