Powercolor 7990

[crazyates]

17 phases !?!??!?!?!?!!

With 500+ Watts running thru there, i'm assuming they prolly had to just to keep the temps down.

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[Mousepotato]

Not to sound like a huge n00b, but what is a "phase"?

[rjk]

Not to sound like a huge n00b, but what is a "phase"?

Since power regulators are cheap, they are usually run in parallel instead of using one or two really big ones. The number of parallel regulators is the number of phases. Usually, each regulator chip also has it's own control signal pin from the voltage (PWM) controller, so they can be controlled individually for efficiency.

[MrTeal]

Not to sound like a huge n00b, but what is a "phase"?

Very simply, think of it as 17 power supplies in parallel. It's a little more complicated than that (the different phases in the switching power supply switch at different time to help reduce ripple and whatnot), but that's basically what it does.

[ssateneth]

Not to sound like a huge n00b, but what is a "phase"?

google it.

in an extremely dumbed down way of putting it though, more phases = better

I believe more is supposed to fight any sort of voltage droop from high loads. Usually doing a higher power load will reduce the voltage consequently, unless you have higher quality power hardware. you can see this easily with any sort of hardware monitor program and a stress tester. chances are if you run a stress tester program, your 12v sensor will drop a couple of percent, maybe less if you have very good quality power supply. The same happens to cpu core voltage. if you have bad power hardware on the motherboard, your core voltage will droop under stress (my evga 790i sli ultra had this problem bad. lost nearly 0.08v when under full load on quad core overclock)

If you couldn't tell, I don't know what constitutes as a "phase" either I can count them on a motherboard though.

[bulanula]

I can count them on a motherboard though.

Never could. I don't also understand the difference between say 24 phases and 8+2 or something like that for mobos.

I think the question here is go 7970x2 or reference 7990s ( if these even exist )

[cmg5461]

I don't also understand the difference between say 24 phases and 8+2 or something like that for mobos.

The more phases, the less voltage spikes.  You know, when cpu's are oc'd to 1.4v.. a voltage spike could fry it.

[MrTeal]

I can count them on a motherboard though.

Never could. I don't also understand the difference between say 24 phases and 8+2 or something like that for mobos.

I think the question here is go 7970x2 or reference 7990s ( if these even exist )

But as always, Wikipedia knows.

http://en.wikipedia.org/wiki/Buck_converter#Multiphase_buck

Say you have a 10 phase power supply that runs at 100kHz. That's one switching every 10us. Now, instead of switching them all at the same time, you'd switch one at t=0, one at t=1us, the next at t=2us ... and the last as t=9us, before the cycle repeats. It's multiphase because they're the same supplied, but they're out of phase with each other, similar to how 3 phase AC power lines are 120 degrees out of phase.

[multi#lord]

http://www.techpowerup.com/167182/PowerColor-HD-7970-X2-Devil-13-Taken-Apart.html

7970 X2 Board shots: (More in above link)

[ssateneth]

Now thats the porn I came here to see.

[Aseras]

Jesus, 3 8 pins and an external power supply jack.

[crazyates]

Jesus, 3 8 pins and an external power supply jack.

That's not a DC jack. That's the big red OC button seen in the other pictures.

[bulanula]

Forget about this monster.

Where is my tame 7990

With FPGAs and ASICs anyone buying this overpriced crap is a mugu / fool !

[Tomatocage]

Agreed.  I'm keeping my eye on Computex for the (alleged) 7990 announcement.

[bulanula]

Agreed.  I'm keeping my eye on Computex for the (alleged) 7990 announcement.

The reason I am thinking is because I would say the regular 7990 cherry picked low leakage chips would be easier to get maximum MH/W compared to the above GAMER chips which need like 500 W alone to function properly.

It looks like it was made to OC not be efficient for mining at all 

[Mousepotato]

The reason I am thinking is because I would say the regular 7990 cherry picked low leakage chips would be easier to get maximum MH/W compared to the above GAMER chips which need like 500 W alone to function properly.

Good point! I'll take cherry-picked chips (higher ASIC quality?) over whatever hodge podge of 7970 GPUs that PowerColor decides to slap onto the same board.

[bulanula]

The reason I am thinking is because I would say the regular 7990 cherry picked low leakage chips would be easier to get maximum MH/W compared to the above GAMER chips which need like 500 W alone to function properly.

Good point! I'll take cherry-picked chips (higher ASIC quality?) over whatever hodge podge of 7970 GPUs that PowerColor decides to slap onto the same board.

Yes but I think AMD has given up with 7990 as it cannot compete with GTX 690 at any rate ( gaming / perf ) and mining is small marketshare and they also had thermal issues trying to cool so much heat with only one fan.

Hope I am wrong !

[waterboyserver]

This is kind of a interesting concept, though do not how long/valuable this would be for mining: two Radeons 7970s (?) integrated on one motherboard, but no pcie expansion slots:

http://vr-zone.com/articles/asus-zeus-combines-x79-hedt-with-dual-gpu/16152.html

[bulanula]

Looks really nice but too expensive and not enough quantities and also much more expensive than just two 7970s and cheap mobo I think especially using SB-E CPU ? No way it's gonna be cheap !

[MrTeal]

There can't be 7970s under there, at least not full ones with stock clocks. There's just nowhere near enough surface area on that heatsink to dissipate 500W, unless there's barbs sticking out somewhere I can't see.