I have a Compaq Presario AMD 3800+ (2.4 GHz) system. Only 1 HD at present but will probably put in a 2nd 7200 SATA drive at some point. Most of the perif are built in although I have a 24 bit Audigy SE sound card in the unit currently. Currently have 2.5 GB ofg 5300 DDR2 RAM. I forget offhand what the power supply is in the unit currently but I'm fairly sure it is either a 300 or 350 w power supply.

I just ordered a 8800 GT 512 MB card. I was wondering who else already has one of these newer cards and what size power supply the beast requires so I know whether or not I need to go out and upgrade the PS in my unit as well.

Thanks!

You are pushing it. I have seen an article where the max power draw is close to 200W on that card. So if 100-150W is enough for everything else, and stability then you are alright.

But your CPU and mobo are a serious bottleneck for this video card.

If I recall correctly the mobo has a PCI-e with a 16 pipe. I'm not planning on OC'ing just using it as is.

This PC is not necessarily going to use the card at max capacity. This system is a fill in cause the old system died and don't have the funds to build an entirely new rig as I want it spec'd so I'm going to use this card in the temp system until I get the funds put together to make a better system and then will transfer the card over.

In the mean time I just needed to know for sure what kinda power draw I would be looking at.

The card itself draws less than 12A (150W). Still pushing it with that PSU though.

I was looking at power supply alternatives.

The local store has:
Thermaltake TR2 430 W which supplies 18A on the 12V rails ... for $25 (after rebate)

Antec Truepower Trio 650 W which supplies 18A or 19A on the various 12V rails ... for $90 (after rebate)

and OCZ StealthXstream 600 W which supplies 18A on all the 12V rails... for $90 (after rebate)

The first one is nice just from a price point perspective. The others would certainly have the juice but would probably be overkill considering the rest of the system. Anyone have any bad experiences with any of their mfg's?

Just helped ouyt a friend and he also has a Compaq with the same specs as you and his PSU is only 250watt. You will need at least a 550 PSU from a Tier 1 PSU manufacturer, I would suggest 600w to 750w Range. Also make sure you get one with these dimensions > 150x85x140mm (5.86x3.46x5.47 inches), so it will fit in the case you have from Compaq.

I recommend buying the psu that is overkill, because you can use it in your next build.

Of the three PSUs that are listed, I'd go with the OCZ gamestream 600. Its overkill at the moment, but will be useable for future builds.

You don't need a tier 1 PSU by any means. That's nonsense. A tier 2 PSU is well good enough and even a tier 3 PSU would probably handle your computer just fine. For that matter, if you don't intend on building a complete computer for a couple years, a 500wt PSU would handle your present computer with a 8800 GT 512 card quite well.

My friend has a Compaq computer with similiar specs and he just recently installed a 8800gt. He has had it running for about a week now and it is performing flawlessly, even throughout long gaming sessions (3+ hours at a time). I would imagine that you will most likely be fine. I would try it first, and if you experience issues, then order a PSU.

350 is a bit low...for that card, I'd want to match its recommended current rating at 430W or higher.