video card upgrade without power supply upgrade???

[pbaiocco]

i was looking at the EVGA 7900GT but i need a min of 400watt power supply and my dell e510 only can put out 350w max and i cant find a transformer that fits my chasis, so then i started looking at teh 7600 series but there are so many different models and not sure how it compares to the 7900 in real life. this it teh model i was looking at <http://www.circuitcity.com/rpsm/oid/147048/rpem/ccd/productDetail.do#tabs> any suggestions?

[Murf]

That system comes with a power supply that has a Output Wattage: 305W maximum continuous.

The EVGA 7900GT requires:

Minimum of a 400 Watt power supply.
(Minimum recommended power supply with +12 Volt current rating of 20 Amp Amps.)
Minimum 500 Watt for SLI mode system.
(Minimum recommended power supply with +12 Volt current rating of 28 Amp Amps.)

The bold above is the key: Amperages not wattage.

Your motherboard has the following:

2 PCI slots
1 PCIe x 1 slot
1 PCIe x 16 (graphics) slot

So yes that card would fit, but may not work.

Dell Power Supplies are proprietary

This card will work well with your existing system:

Radeon® X700 PRO for PCI Express http://www.newegg.com/Product/Produc...82E16814102414


http://www.pcper.com/article.php?aid=74&type=expert

[pbaiocco]

how does the radeon compare to evga though, ive only dealt with evga in the past so im not too familiar with radeon?

[Murf]

ATI Radeon and Nvidia chip cards are both at the top of the line.

For example the card you were looking at:

EVGA 7900GT

Chipset: NVIDIA
GPU: Geforce 7900GT
Core Clock: 500MHz (Standard 450MHz)
Memory Clock: 1500MHz (Standard 1320MHz)
Memory Size: 256MB
Memory Interface: 256-bit
Memory Type: GDDR3
RAMDAC: 400 MHz

ATI X700 Pro:

Chipset: ATI
GPU: Geforce Radeon X700PRO
Core Clock: 425MHz
Memory Clock: 860MHz
Memory Size: 256MB
Memory Interface: 128 bit
Memory Type: GDDR3
RAMDAC: 400 MHz

Yes the EVGA 7900GT is statistically a better card, but $165 USD more. Most High End Video Cards will require hugh amperage to run around 30Amp on the +12v side.

Open your case and there should be a sticker on your power supply, on that sticker it gives the various amperages for the different voltages. What amperages does it list under +12V

This will drive which video card you can get, and whether it may be worth the investment for a new Power Supply that meets the requirements of Amperages.

[pbaiocco]

the out put is +5V =22A max im taking and electromechanical class right now in class and have some understanding of this but still not sure what to look for when shopping for a video card. max watt output is 305W

[Murf]

Ok great then:

There are three primary voltage rails inside of the power supply: +3.3V, +5V and +12V. Each of these supplies power to the various components of the computer system. It is the combined total power output of all these lines that make up the total power output of the system. The formula used to do this is:

• Wattage = Voltage * Amperage

So, if you look at a power supply label and it shows that the +12V line supplies 18A of power, that voltage rail can supply a maximum of 216W of power. This may be only a small fraction of say the 450W the power supply is rated at. The maximum output of the +5V and +3.3V rails would then be calculated and added to the overall wattage rating.

12V Rail
The most important voltage rail in a power supply now is the +12V rail. This voltage rail supplies power to the most demanding components including the processor, drives, cooling fans and graphics cards. All of these items draw a lot of current and as a result you want to make sure that you purchase a unit that supplies enough current to the +12V rail.

If you are going to keep the existing power supply, then you will need to find a card that would not require more than 22A and the +12v rail.

The problem you are faced with is your 305watt power supply; The peak output rating is the highest amount of power the unit can supply, but this is only for a very brief time.

Units can not continuously supply power at this level and if it attempts to do so will cause problems. You want to find the maximum continuous wattage rating of the power supply. This is the highest amount that the unit can supply stably to the components. Even with this, you want to make sure the maximum wattage rating is higher than you intend to use.

Bottom Line: If you want a high end video card, like the ones you have been looking at a replacement power supply is in order. pci ex cards do need power much more than a AGP card.

If you keep the existing power supply then cards like these will work great:
http://www.newegg.com/Product/Produc...82E16814130030

Otherwise you would have to go to a PCI video card e.g.,

http://www.newegg.com/Product/Produc...82E16814121015
http://www.newegg.com/Product/Produc...82E16814145087

[pbaiocco]

thank you very much for the information. i think im gonna go for the evga 7600 and do a power supply ugrade, i found a 400 watt transformer that will fit my chasis and my only concern is that like you said the 400W max output isnt continuous and the minimum requirments for teh card in pci-ex is 400w so im not sure if this will be sufficient or i might have to look harder for a transformer that has more than 400W max output.

http://www.circuitcity.com/ssm/EVGA-...oductDetail.do

[pbaiocco]

do all the connectors mate with my pc no matter what transformer i buy???

[Murf]

Good card.

I did some research and appears your model Dell does not have a proprietary Power Supply, therefore, any ATX power supply will fit, as long as it has a 24 pin ATX connector.

Example: A lot of DELL user are using this one

http://www.newegg.com/Product/Produc...82E16817104154

[pbaiocco]

excellent, and ive been checking out newegg.com and i think i will order everything from them. they seem to be the place to go. thanks again for the help.

[Murf]

Circuit City is OK, but NEWEGG is very well known, super service, quality products and if necesary super customer service.....no I do not work for them, but buy a lot from them.

[pbaiocco]

one last check before i order the products, the power supply you gave for an example will sufficiently supply power @450W max to the 7600GT KO with a 350W min at 18A or 20A (cant remember) or should i go to the 550W model just to be sure or is it not that critical?

[Murf]

That particular one:

Maximum Power: 550 Watts
Sustained Power: 450 Watts
Supports ATX/BTX/PCI Express/SATA,
OCZ PowerWhisper Technology with 120mm fan

+12v rail =26A

[REDDOMNI]

i was also looking to upgrade my power supply so I could get a better video card for thsi system but the link for the power supply in newegg is gone. They must have sold out
1. what do you recommend for a power supply?

2. which video card for great game performance?

you can email me also
thanks Brian