Topic: 7990? Guess on cost, power usage, output? (Read 7863 times)

Inaba bought first and it's new in box...

any test screen shots to show how it mines?

tried to find figures and could not, Inaba said it's still in the box

ASIC?

buy one for 90BTC: https://bitcointalksearch.org/topic/m.1231986

If this true,then the hashrate is more that double what my GPU can deliver me (400Mhash/s stable OC'd).Uses 220W I think at that hashrate.That HD7990 sounds like serious business if you have the PSU for it (which I don't atm). On HD6990 I hear that the extra power draw (above 375W) is designed to come from the PCI-E power connector but means you need a strong PSU with good connectors (since the PCI-E card slot can't deliver more than 75W).

Why?

For those of us running mainly 5830's, I think that the upcoming 1.5GB iteration of the 7950 will reign supreme.
It should use LESS power than a 5830, while hashing away at a solid 450-500 MH/s in the process.

Currently, those 'in the know' report approx a 8-10w difference between the 5830 1GB and the 7950 3GB (the 5830 using less power currently), so I can only assume that the 1.5GB 7950 will be even more power efficient and be a nice upgrade/replacement for some ageing 5830's.

Maybe ATI/AMD should just man up and add another pcie power connector.

Your wattage claims are unrealistic.  Looking at TDP is useless. 5970 is rated for 300W TDP but pulls <250W when mining and that is clocked up to 820 from a stock of 750 Mhz.  Even in games 5970/6990 don't pull TDP.  TDP is max thermal design power.  The maximum power the card can safely dissipate without damaging itself, other components, or creating a fire hazard.

TDP =/= operating wattage.  Not for gaming, not for mining.

I agree on availability and MSRP being $849.  I doubt you will see them on ebay for $1200.  Supply will only be tight for a month or so.

The 7990 will be clocked a 825 vs 950 on 7970 that is ~14% reduction in power.
The chip used in 7970 has a 1.025V power state despite no shipping card using that which is likely reserved for chips which will be binned for 7990.
Power is reduced by the square of the voltage change.  So a 10% drop in voltage is a 19% drop in power.  Combined it is ~30% savings.  

So 200W * 2 * 0.7 = ~300W under gaming conditions.  Mining will be less.  At stock core and reduced memclock the 7970 has no problem being aggressively undervolted (lots of die is idle so stock voltage isn't necessary).

From the 7970 review thread

Thus 7990 should be able to clock at LEAST to 7970 stock core clock and be undervolted and memory downclocked.
Thus 1.1 GH/s sould be fairly easy and at <280W when undervolted and memory downclocked.

1.2 GH/s may be a stretch though.

Umm .. no ... not quite.

Will be released between March and April, but only after all other offerings, i.e. 7770, etc.
Will cost $849, list ... there will be an immediate shortage and you will see street prices for $999 ... eBay listings will have them for $1100-$1200.
Will hash at 975 mhash/sec @ 820 mhz, if overclocked we will be lucky to see 1100 mhash/sec @ 925 mhz.
Will use 375 watts.

Here is the reason ... currently the 7990 has a power problem. The power demands of the 7970 are greater than a 6970, but a 6990 was basically a underclocked dual 6970 and was maxed out on power. Very little overclocking room before saturating the available 375 watts. The 6990 allowed raising the voltage and bumping power up to 420 watts but this was beyond spec and some poorer quality molex connectors didn't survive.

Remember they don't tune these things for miners with low mem speeds and all.

So ... what we are looking at is is a power consumption of 232 watts at stock clocks/mem/voltage. So two of them would be around 464 watts. Now moving to a single fan might shave off 20 watts (30 watts tops) ... so 430 watts at stock voltage/mem/clocks... this is a problem .. that is where they want to be after overclocking.

So they will have to introduce them at a lower clock rate, perhaps 820 mhz instead of 925 mhz ... which would shave it to roughly 200 watts per gpu. Again a little fan savings... and bam ... we are at 385 watts ... damn ... still too much ... especially since the added PCI-e bridge on board uses 5-7 watts. So we are actually at close to 392 watts again ... not a lot of margin.

Plus they don't typically ship with settings that run absolutely to the bleeding edge of the spec ... they want you to be able to overclock some..

So ... what can they possibly do ... they will undervolt them stock, which will limit the ability to overclock like a 7970 to 1100-1200 mhz.

I expect them to intro closer to the 1.00-1.05 volt mark ... this would put the power about 25-50 watts less per gpu.

So .. then you are looking at;

820 mhz clock @ 1.05 volts using about 335 watts doing 975 mhash/sec

or

820 mhz clock @ 1.00 volts using about 300 watts doing the same hash rate.

Remember they want you to have plenty of room to overclock and buy ridiculous cooling hardware and publish tons of reviews, etc, etc... this is all good media for them...

About what I think.

Though $850 and ~275 watts while mining. Then hope at best March though likely near Nvidias release.

When will the 8950 be released?

How long will these 7990's be the "king" of cards?

Will the 8950 be released early enough to compete with FPGA mining?

I will gladly take 3 of them :-)

Unfortunately you seem to know as much as I...

Hi All,

From what I have been able to find and using other related info I have come up with this guess on the 7990's. Please tell me how and why you think these numbers could be improved.

Will be released in March.
Will cost $800.
Will hash at 1.2G.
Will use 300 watts.
(slight undervolt, mem down clock to 300 and the core at 1100)

Thanks.