6800 Ultra does NOT need 130W adapter

[ciVick_EX]

That's right, but there is a small price to pay. I read several threads concerning 6800 ultra upgrades in 9300. Apparently Dell's last 9300 bios, the A05, recognizes the card. However, the card still runs in low power mode as you boot it so read on as to see how to get it to work at (nearly) full speed.

I can't take credit for the original idea, but I do want to say that it is something true for the 6800 series. This gives hope for the 7800 GTX as well; perhaps a 130W adapter is not needed there either.

Basically, the problem is not the core voltage and core speed as most people think. In fact, it is the DDR3 memory that causes the card to run in low power mode. I do not know if it is increased power consumption (vs the DDR of the 6800 go) or simply a bios setting that causes the card to go to low power.

In order to get the card to run under regular core speeds, the memory has to be downclocked to below the stock value to get it to run on the 90W adapter. So, I used nibitor to simply modify the bios to have 400 MHz memory (that's 800 DDR) rather than 526 or whatever it is stock. That's all you have to do!

Now, my hopes are that Windows overclocking will allow for the memory to be reclocked higher and even overclocked. I have not yet tried this yet. I will do it over the weekend and report in this thread. I'm fairly certain the core can be overclocked but that has yet to be tested as well. When I get my hands on a 7800 card I will test it as well.

Hopefully this will save people some money (no need for adapters, 9 cell batteries, or bios changes). Comments/questions are welcome...

[SolApathy]

well...with a 6 cell battery you are talking extremely short battery life #1, eps if you are tryig to game on it.

#2. Using a 90 watt adapter you are going to be constantly running that adapter at a high load ratio, increasing heat & reducing it's overall lifespan. There is a reason they use a 130 watt brick. Esp if you are charging the battery & running a game at the same time.

It's probably a nice work around if you are in a pinch but I would not recommend it for normal usage.

[zzpulp]

yeah the memory was rated to run 1100 mhz (and runs 1200+ fine so far as I've seen) so thats quite a step down...The core clocks will still make it beastly though but ah, some overclocked 6800go's can come close in terms of performance minus the DDR3 mem...good for the minimalists out there though I guess

[ciVick_EX]

Let's not be hasty and jump to conclusions.

First off, the 6 cell battery is fine in regular windows. That is b/c the card will run in low power mode (or rather it should) while not running 3D applications.

Second, I have some serious doubts about the 90 Watt adapter being insufficient in the long run as you say. I will test the cards more thoroughly like I said, but I don't have the time at the moment. The reason I'm saying this is b/c the 9400 laptops are able to run 7900 GS cards at some very high core clock & memory speeds. The voltages are different between the types of cards, but we are talking about wattage here, not voltage. A sort of guestimate of power usage would be the heat given off by the cards... so that's the basis I will be using when overclocking the 6800 Ultra I have right now.

That brings me to my last point. We don't really know why the 6800 boots in lower power mode if on a 90 W adapter. All I want to find out is exactly how high can the memory go. Current eBay prices for 6800 Go and Ultra are approximately the same, so why not get a better card for the same price?

[zzpulp]

you cant really judge by heat...different chassis, two heatpipes, effeciency (110 nm vs 90 nm)...And also I thought the card doesnt run full clocks because powermizer looks for the 130 W adapter and if its not there it wont run them just as it would if you were on battery

But eh, Im not trying to bash...if theyre the same price definitely hop on the ultra and run it at whatever settings you want to

[dave-p]

Its better if you use the 130 watt brick, you maybe able to run it with the 90 watt but your taxing the hell out of it

[ciVick_EX]

Yes. I intend to find out exactly how much it gets taxed :)

[dgcaste]

I'll tell you why, the 6800 Ultra is frickin hot. Get the 7800GTX, its price has dropped recently.

[ciVick_EX]

Well the 7800 unfortunately is still going for 350+ on ebay.

Preliminary testing results are good. The 90 Watt power brick can indeed handle the card at full speed. I played World of Warcraft at highest possible settings for about 6 hours. The card was overclocked at 490/1100 and it never waivered (but it did get hot!!!). The power brick also got hot. I have had multiple such gaming sessions and the power supply has yet to give out.

There is one annoying feature though. Apparently, whenever I put the PC in sleep mode (which is a lot in my case) it tends to be a little POS and put the card in low power mode whenever I pop it open!! So that means I have to restart the dang system.

BTW I got about 6k marks in 3DMark05 with this thing OC'ed (I used a modified unlocked bios in order to get it to boot full power). I can't wait for the 7800's to go down a bit so I can try one of those.

[ciVick_EX]

I'm afraid I have some bad news. The 90 Watt adapter indeed cannot handle the high power requirements of the memory. It cuts out at speeds >1000 MHz DDR. This sucks, but the core can still run at OC'ed speeds.