5870 X2

[dan]

So I'm getting my other 5870 back from my son (buying him a new GTX 580) and will have two. I have two boxes. One has a 750W PSU, i7 860 and the motherboard has 2 PCIe 16x in slots 1 and 4. The other has 850W PSU, i7 950 and the motherboard has 2 PCIe 16x in slots 1 and 3.

I'm thinking of dropping them both in the box with slots 1 & 4 as PCIe. What do you all think?

Thanks,

Dan

[Maxwell]

Putting them in slots 1 and 4 will help a lot with cooling. I've got a 2x5870 box and had cooling problems until I moved the cards far apart.

The 750W PSU will probably be ok, but I'm not too sure - I tend to go overkill with PSUs, so someone with more experience will have to do the math there.

[dan]

Putting them in slots 1 and 4 will help a lot with cooling. I've got a 2x5870 box and had cooling problems until I moved the cards far apart.

The 750W PSU will probably be ok, but I'm not too sure - I tend to go overkill with PSUs, so someone with more experience will have to do the math there.

I'm kinda worried about heat with them being in 1 and 3. Right now with just one care my system eats up 415W with Boinc on full blast.

Dan

[JerWA]

In theory, the PCIE spec says 6 pin power = 75 watts max. So, two = 150.

8 pin power is 150 watts.

The problem with guessing power this way is that physically the 6 pin cabling is capable of way more than 75 watts, so it's kind've up to the GPU manuf to stay within spec.

[John P. Myers]

In theory, the PCIE spec says 6 pin power = 75 watts max. So, two = 150.

8 pin power is 150 watts.

The problem with guessing power this way is that physically the 6 pin cabling is capable of way more than 75 watts, so it's kind've up to the GPU manuf to stay within spec.

Very true. And it's easy to overclock your GPU outside of those specs.

Something to note on power draw: you said your system is using 415W with 1 5870 (you'd still be fin adding the 2nd to this same box). Is that measured at the wall socket? If so, your power supply is actually only creating 291W for your computer which gives you tons of room for upgrading and overclocking.

[dan]

Very true. And it's easy to overclock your GPU outside of those specs.

Something to note on power draw: you said your system is using 415W with 1 5870 (you'd still be fin adding the 2nd to this same box). Is that measured at the wall socket? If so, your power supply is actually only creating 291W for your computer which gives you tons of room for upgrading and overclocking.

Interesting. Why 291W? The measure of 415 is from the UPS, so kinda at the wall socket.

[DrPop]

Efficiency vs load...you're pulling in a lot more at the wall than you're putting out into the system when converting AC to DC.

Now...just for kicks...any way you could swap PSUs? Like put the 850W into the rig with PCIe at slots 1 and 4? Either way you should be fine with the 750W, but you'll save $ on your electric bill if you run the PSU at less % of its rated output. Again, this having to do with efficiency.

I just have to ask this because I'm curious, though - any reason why he's the one getting the GTX 580? You could get a lot more points with that GTX 580 on PrimeGrid than you can with the 5870 on any ATI project right now. Just the way the cookie crumbled this time around...used to be the other way around until the PG CUDA app came out. For example, my lowly GTX 465 is smoking my 5870 O/Ced to the hilt in points per day, and I paid 1/3 the price for the 465! If only I'd known back then and bought THREE GTX 465s, LOL! :p;)

[dan]

Efficiency vs load...you're pulling in a lot more at the wall than you're putting out into the system when converting AC to DC.

Now...just for kicks...any way you could swap PSUs? Like put the 850W into the rig with PCIe at slots 1 and 4? Either way you should be fine with the 750W, but you'll save $ on your electric bill if you run the PSU at less % of its rated output. Again, this having to do with efficiency.

I just have to ask this because I'm curious, though - any reason why he's the one getting the GTX 580? You could get a lot more points with that GTX 580 on PrimeGrid than you can with the 5870 on any ATI project right now. Just the way the cookie crumbled this time around...used to be the other way around until the PG CUDA app came out. For example, my lowly GTX 465 is smoking my 5870 O/Ced to the hilt in points per day, and I paid 1/3 the price for the 465! If only I'd known back then and bought THREE GTX 465s, LOL! :p;)

It's a mess the box with my 850 in is s'pose to be my gaming/development box. The i7 950 is in that box, and the i7 860 in the other. So it would be better to swap the video cards, assuming two 5870 in CF will out perform the 580. But I have 5 500GB drives in a raid 5 in the box with the 750 PSU that smoke my SSD in the 850 PSU box in throughput. I have no idea where to begin. I hate rebuilding drives as that is a day long endeavor. Time to build a new box that smokes both of the other two...

[Fire$torm]

........I hate rebuilding drives as that is a day long endeavor. Time to build a new box that smokes both of the other two...

I like the way you think :-bd

[DrPop]

Time to build a new box that smokes both of the other two...

LoL! :D I feel a new Highliner coming on the team! :cool:

[joker]

Another one!!!! How am I supposed to keep up with all you guys upgrading!! ;)

[dan]

Another one!!!! How am I supposed to keep up with all you guys upgrading!! ;)

It's the only way I'm gonna catch you <):)

[dan]

Just installed the second card Total wattage is 614.

[Mike029]

Just installed the second card Total wattage is 614.

Ouch, is that on the 750w psu? Pop is right, you may want to upgrade.

[dan]

Ouch, is that on the 750w psu? Pop is right, you may want to upgrade.

Maybe not. The Wattage is measured at the UPS. So it's actually needing around 80% of 613 right now and should be ok. Right?

Anyone know of a software tool that measures voltage consumed by the box?

Thanks,

dan

[DrPop]

Right. So you're pulling 613W from the wall? Should be OK with that 750W PSU then. As long as it can handle the Amps on the 12V rails, you're fine. What model is it?
Also, with DNETC gone, I'm betting you'd get more from a GTX 580 on PG than 2 5870s on MW. Not that it matters much, but you were talking about trading GPUs with your son and all...
Have a great time with such a powerful rig! :D

[dan]

Right. So you're pulling 613W from the wall? Should be OK with that 750W PSU then. As long as it can handle the Amps on the 12V rails, you're fine. What model is it?
Also, with DNETC gone, I'm betting you'd get more from a GTX 580 on PG than 2 5870s on MW. Not that it matters much, but you were talking about trading GPUs with your son and all...
Have a great time with such a powerful rig! :D

The PSU is a corsair. For the 5870s, I have two Sapphire Vapor-X cards. Ran 3Dmark 11 this morning and the CF rig scores 23% above the 580. Hope Dnet comes back. I think this setup would be real nice with Dnet scores.

[Beerdrinker]

Maybe not. The Wattage is measured at the UPS. So it's actually needing around 80% of 613 right now and should be ok. Right?

Anyone know of a software tool that measures voltage consumed by the box?

Thanks,

dan


http://www.extreme.outervision.com/psucalculatorlite.jsp

[joker]

I need more power captain! (or is it CAPTION??) :cool:

[DrPop]

The PSU is a corsair. For the 5870s, I have two Sapphire Vapor-X cards. Ran 3Dmark 11 this morning and the CF rig scores 23% above the 580. Hope Dnet comes back. I think this setup would be real nice with Dnet scores.

Nice, so the PSU is a solid one, then. Great! No need to change it.

RE: the points thing - I totally understand what you mean, the 2 HD5870s in CF are going to spank the GTX 580 in most games at high resolution. (Like the 3Dmark 11 score).
However, PG is giving out points like CANDY. I mean, the points given for a high-end CUDA card are not proportional to what MW can give you on the high end ATI stuff.
Hope that makes sense.
Put another way, yes, the HD5870s in CF are more powerful than the GTX 580. But, that "extra power" is not being rewarded as much, because the credits aren't given out as freely. My lowly GTX 465 will get the same amount of credit in PG as those 2 HD 5870s will get in MW combined. It's not an apples to apples comparison - it's just that the GTX 580 will get you more points per day.

If DNETC comes back, it will be a different story, so I'm holding out for that as well! :D

Congrats on the killer rig! And, last but not least - thanks for being active on the team! ;)

[dan]

RE: the points thing - I totally understand what you mean, the 2 HD5870s in CF are going to spank the GTX 580 in most games at high resolution. (Like the 3Dmark 11 score).
However, PG is giving out points like CANDY. I mean, the points given for a high-end CUDA card are not proportional to what MW can give you on the high end ATI stuff.


My GTX 580 get's 3 times the points on PG versus my two 5870s on MW :(

[Dandasarge]

http://www.extreme.outervision.com/psucalculatorlite.jsp

Thats a pretty good link thanks Beer!

[Fire$torm]

I need more power captain! (or is it CAPTION??) :cool:

Oh bite me.......