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 Post subject: 9800 GTX+ 55 nm draws much less power
PostPosted: Fri Dec 05, 2008 6:15 am 
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Review at Xbitlabs, page 5: http://www.xbitlabs.com/articles/video/ ... html#sect0
I am so impressed that I find it hard to believe. Can the power draw drop so much, when a large part of it is due to the memory at 2,200 MHz?
The one with the custom PCB looks very tempting, since it draws only 76W and is only 23 cm long, so it fits in a Solo.
PS. The massive drop in power draw may not apply to other 55 nm 9800 GTX+ cards, so don't take this as granted.
PS2. There may be some 65 nm 9800 GTX+ cards, also by Palit, that look the same but draw a lot more power. I'd like to know how to distinguish between them.


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 Post subject: Re: 9800 GTX+ 55 nm draws much less power
PostPosted: Fri Dec 05, 2008 6:42 am 
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Tzupy wrote:
Can the power draw drop so much, when a large part of it is due to the memory at 2,200 MHz?

Why would the memory require much power? The numbers make sense to me. The 65nm GTX+ was basically pushing the limits. The 55nm part is relaxed at the same speed. Probably simple V^2 power scaling on the GPU.


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 Post subject: Re: 9800 GTX+ 55 nm draws much less power
PostPosted: Fri Dec 05, 2008 11:49 am 
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QuietOC wrote:
Why would the memory require much power?


http://www.xbitlabs.com/articles/video/ ... 0gt_5.html

This review by xbitlabs shows the difference between an otherwise identical 8800gt, but one has 256mb of ram and the other 512mb of ram.

The power difference at load is 33w. So obviously memory can and does suck much of a video cards power.

So if you figured 256mb of memory is around 30w of power dissipation at load, when looking at graphics cards with 512mb or 1gb of memory, you really need to drop around 30-90w of power off the total load power consumption to get the actual GPU power dissipation so that you can figure out if an AC S1 aftermarket heatsink can passively cool it or not.

They really need to figure out a way to test actualy GPU power dissipation, and not just the entire video cards power dissipation since aftermarket VGA coolers only have to deal with the GPU heat, not the memory heat.


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 Post subject: Re: 9800 GTX+ 55 nm draws much less power
PostPosted: Fri Dec 05, 2008 12:18 pm 
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Aris wrote:
The power difference at load is 33w. So obviously memory can and does suck much of a video cards power.

There is no memory besides RAMBUS and FB-DIMMs that draws anywhere near 33W. I don't know where people are getting this. The difference between the two 8800GTs has nothing to do with the amount of memory. Sure, more or faster memory chips wlll consume some additional power, but no where near 30W.


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 Post subject:
PostPosted: Fri Dec 05, 2008 12:41 pm 
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Wtf? I didn't know there was a 65nm 9800GTX+? I thought the whole point of the + was that it went to a 55nm. a 65nm 9800GTX+ is an overclocked 9800GTX.

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 Post subject: Re: 9800 GTX+ 55 nm draws much less power
PostPosted: Fri Dec 05, 2008 1:17 pm 
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QuietOC wrote:
Aris wrote:
The power difference at load is 33w. So obviously memory can and does suck much of a video cards power.

There is no memory besides RAMBUS and FB-DIMMs that draws anywhere near 33W. I don't know where people are getting this. The difference between the two 8800GTs has nothing to do with the amount of memory. Sure, more or faster memory chips wlll consume some additional power, but no where near 30W.


So then how do you explain the power consumption difference? Everything else between the two cards is identical. Same manufacturing process, same type of memory, same GPU core, same core clock, same memory clock, same bus interface.

the ONLY difference is an additional 256mb of memory, and the power difference is 33w. So what else do you think is causing the increased power usage other than the memory?

Ch0z3n wrote:
I thought the whole point of the + was that it went to a 55nm. a 65nm 9800GTX+ is an overclocked 9800GTX.


It wouldnt be the first time. Most of the entire 9 series linup is just rebadged versions of the 8 series. The new manufacturing process didnt start until recently. When the 9 series was originally released, they were identical to their 8 series counterparts in every way.

IE: an 8800gt 512mb is the exact same card as a 9800gt 512mb. unless you get the new 55nm manufacturing process. which as has been stated earlier can be difficult to diferentiate between the older 65nm parts.


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 Post subject:
PostPosted: Fri Dec 05, 2008 1:42 pm 
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How recently are we talking about? the 9800GTX+ hasn't been out all that long.

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 Post subject:
PostPosted: Fri Dec 05, 2008 2:18 pm 
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heres what wiki says: http://en.wikipedia.org/wiki/GeForce_9_ ... e_9800_GTX

"GeForce 9800 GTX
On April 1, 2008 the GeForce 9800 GTX was officially launched. It was basically an 8800 GTS 512mb with two SLI connectors, higher clock speeds, and support for Nvidia Hybrid Power, a technology that allows the discrete GPU to shut off during non resource intensive applications, and instead use the integrated GPU. With these extra features though, a high price came too."

"In July 2008 nVidia released the 55nm refresh of the 9800 GTX: the 9800 GTX+. It has faster core (738 MHz) and shader (1836 MHz) clocks."

So it seems the + does mean the 55nm version of the 9800gtx.

Unfortunately they didnt do this + theme with the entire series 9 of cards:

"The 9800GT is effectively a rebranded 8800GT, although some are being manufactured using a newer 55nm technology instead of the older 65nm first debuted on the 8800gt"


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 Post subject:
PostPosted: Fri Dec 05, 2008 2:20 pm 
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yeah, that't why I was confused my the "9800GTX+ ref 65nm", that shouldn't exist.

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 Post subject:
PostPosted: Sat Dec 06, 2008 6:54 am 
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An older article at Anandtech tested an early 9800 GTX+, and found that it draws MORE power than the GTX 260, so around 130W.
Link: http://www.anandtech.com/video/showdoc.aspx?i=3340&p=2
Of course, that may have been a 65 nm GPU, with higher voltage and clocks than the 9800 GTX (non-plus), and obviously hungrier.
I know that it *should* have been 55 nm not 65 nm, but nVidia seems to have cheated on this issue.

Regarding the power draw of the memory, IMO it's significant, but unfortunately no one has been able to measure it precisely.
I remember that a Bit-tech article showed the 1 GB 4870 to use 10W LESS than the 512 MB version, and using the same PCB but different memory.


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 Post subject:
PostPosted: Sun Dec 07, 2008 3:02 am 
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EVGA has a shorter 9800GTX+ as well, and it only has one 6-pin PCIe power connector instead of two like other 9800GTX+ cards:
http://www.newegg.com/Product/Product.a ... 6814130420

I don't think anyone has tested this one yet but having only one power connector seems to suggest it has less maximum power draw.


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