Dell video upgrade - ATI x1650XT vs. x1950 PRO

[wildweasel]

I have a Dell Dimension 9150 that currently has a x600 video card which I want to upgrade. The power supply says it has 375 watts but I understand that they rate them very conservatively. I would like to buy a Radeon x1950PRO but the spec says a 450 watt power supply is required. However, the LR review says that the difference in power consumption difference between the 2 cards is not that great (x1650XT 102/197 vs. x1950PRO 104/201 watts idle/load). Does anyone know any more on this situation? Can I use the x1950PRO or am I missing something?

[DMB2000uk]

IF the minimum requirements are 450W then you need to seriously get one at least that.

One of the key reasons they specify the higher wattage is so that the power supply can feed the graphics card enough amps, odds are that your current power supply wont cut it.

Do you know what the x1650xt power requirements are?

Dan

[wildweasel]

According to ATI the x1650XT requires "350-Watt power supply or greater (assumes fully loaded system)". The thing that confuses me is that I have checked a variety of reviews and they all seem to be in agreement that the power consumption difference between the x1650XT and the x1950PRO is less than 10 watts (less than 5%) fully loaded. I also wonder if the 1950 power requirement is based on the XT which I clearly don't have the power for and which was released 1st by ATI! The thing that really bugs me is that the $$$ between the 2 choices are minimal but the x1950 seems to offer significantly better performance.

This would all be easier if I could just upgrade the power supply in my Dimension 9150 BTX case but this does not seem to be available.

[Apoptosis]

It honestly depends on what system you are running... I'm running an unreleased platform with a pair of 8800GTX's that is consuming 720W on 3dmark06... On a different system the same graphics cards are using in the 600W's... so NVIDIA's suggestion of 750W plays it safe. You might be able to get away with a smaller power supply and to be honest you can buy the card and try to get away with it, but if the 12V rail is way below 12.0V or the system crashes during gaming you know you need a new PSU.

[cyberneticimplant]

Yeah, you can try the X1950Pro to see if you can get away with it. I doubt it though. However, you can easily upgrade your PSU and don't have to spend a fortune.

The wattage doesn't really matter. What matters is the AMPS on the 12V rails. Wattage is just marketing.

For example, this 400W PSU has 36A on the 12V rails.

http://www.newegg.com/Product/Product.a ... 6817104953

Compare that to a cheap piece of **** 600W PSU.

http://www.newegg.com/Product/Product.a ... 6817162015

It has only 24A on the 12V. They just jacked up the 5V rail to get the 600W rating.

So that 400W is actually better than the 600W since most of your system is powered by the 12V rail.

[wildweasel]

According to the Dell Forums "The 375 watt Dell PSU has Dual +12 Volt rails of 18 and 17 Amps and a combined +12 volt amperage rating of 30 Amps. " This of course puts it right in the middle of your 2 examples. According to the ATI website the requirements are " 450-Watt power supply or greater, 30 Amps on 12 volt rail recommended (assumes fully loaded system)". To make it even more confusing in the Dell Forums there are a number of folks who are running an ATI x1900 successfully using the same PS, according to ATI the x1900 "requires a 450-watt power supply (and ATI recommends "38 amps on the 12-volt rail)"!](*,)


I guess the only solution (as suggested earlier) is to buy one and try it!!!

[cyberneticimplant]

If it has 30 amps you should be fine.

To make it even more confusing in the Dell Forums there are a number of folks who are running an ATI x1900 successfully using the same PS, according to ATI the x1900 "requires a 450-watt power supply (and ATI recommends "38 amps on the 12-volt rail)"!

It also depends on other hardware you have in your computer. The more hard drives, case fans, expansion cards, etc you have the more power you need. If somebody has only one hard drive, one CD-ROM, and no extra case fans or expansion cards they can get away using a PSU with a lower rating.

[KingM]

I dont know if it'd be worth it, knowing the computer is slightly out dated but I do want to upgrade it, instead of having to buy a whole new system (in the wake of all the new schnazzy games being released). Do you guys think the dimension 1950 would be able to run off of an nVidia 8800? I know i'll have to change the power supply but would eveything else (including the chasis? be able to handle it?
Thanks

[KingM]

....ok so maybe i should have change the subject line, lol, my bad