[John Garland]

System quad opteron 8425 cpu on supermicro H8QMI motherboard with 88 gb ram
with one GTX590 4 minutes
with two GTX590 2 minutes 30 seconds
24 physical cpu cores, no hyper-threading available, the cpu cores don’t help with this benchmark but are nice to have for encoding jobs while my wife does her editing on the other computer.
This older mother board only has PCIE ver 1.1
I have 4 8439 cpus to put in, once I get a cooling solution figured out. I get to upgrade to the fastest old cpus and up the old DDR2 800 ecc ram from 64 to 96gig for less than 300 dollars.
With the old PCIE version a modern card capable of 4K editing would be a waste, but it can still be passed the jobs to encode.
These older 4u cases can be picked up cheap sometimes on ebay. Got this one a few years back for 100 dollars and 75 shipping. It was a little dented and tweaked, but pretty good gauge steel and was easy enough to straighten out. Three hot swap 1200 watt power suppplies was another 150 plus shipping. Pretty nice case with 5 fans and 8 drive bays. It is nice having 3600 watts, still 2400 while swapping supply.

[John Garland]

I don’t know how much bandwidth this benchmark needs, but as for the cards themselves I am sure if they only needed eight lanes they would only have made the card with eight lanes. Sort of like the comedian Ron White joke “I don’t know how many bouncers it was gonna take to throw me out of the bar, but I knew how many they had”. We know how many lanes the card has.

It of course depends on the processor and board. i7-3930k support 40 pcie lanes. throw a third card on it and you are at 48 lanes. some lanes are already in use for other motherboard resources. on the other hand i7-2600K only has 16 lanes. I think your own testing showed how much worse the 2600 was with two and three cards.

my old 5675 processors don’t have built in pcie lanes, they have to be handled by dual 5520 tylersburg northbridge chipsets off the chip, for a total of 72 lanes to handle the motherboard resources.

You asked what the difference in performance might be and that is my best educated opinion. When I jumped my ram from 48 to 96 GB it didn’t help at all. Processor clock doesn’t seem to matter past a point. Lane bandwidth seems to be the main difference between the two setups.

When I put these two GTX580 in a board with a single northbridge, I7-990X, and 24 gig ram at higher speed and clocks, they only score 3 minutes 59 seconds. About the same as when I put a single GTX590 in the dual xeon machine which is of course choked to 16 lanes.

There is a sweet spot for every price range.

Dual cpu isn’t necessary with a 17-3930 and two cards, but if you want to get the most out of three cards, it will be needed.

[John Garland]

I think that is possibly why you don’t see much improvement with three or four cards. Each card is going down to six effective lanes with a single CPU on four cards. It was already choked a little bit on two cards. Supermicro has those big GPU workstations that have four x16 slots with no multiplexing of the lanes. The motherboard I have has two x16 slots, and a x8 which runs the raid card with no sharing of lanes.

The op system and scratch drive are on separate SSD’s. The raw video data is stored on a 8 drive Raid 10 for redundancy and speed.

[John Garland]

I think it is the number of PCIE lanes the dual CPU board can support. The x58 chipset with one cpu is 24 lanes, the dual xeon x8 supermicro is 36 or 38 or 48.

[John Garland]

Hi,
Been using this benchmark for years, finally decided to post scores.
supermicro x8dah dual xeon 5675
96 gig ddr3 1333
two 3gig GTX580 classified

finished 2 min, 55 sec

We have a quad opteron H8qmi with 4 8439 se and 96 gig of ram as well. It has two GTX590 classified GPUs. It has done 2 min 40 sec before.