pci-express 2.0 on a 1.0 motherboard

Hello folks,

I have plans to upgrade my graphics card from a Geforce 7900gt to a Geforce 9 series card, but I was wondering if it would be a wise idea, considering that my current motherboard only has the pci-express 1.0 tech. I am aware that most pci-express 2.0 cards are backwards-compatible with the 1.0 versions, but I am wondering if the smaller bus size would hinder the video card so much that it would be just as effective to get something older from the Geforce 8 series without the 2.0 upgrade.

My motherboard is an Asus A8N-SLI Deluxe with 2 PCI express x16 slots that can run in SLI mode at x8 each and my PSU is 150 Watts. If the above were not possible, would it be any more effective to run 2 cards in SLI, even at the x8 speed each.

Thanks,

Andrew

 

First: your PSU is far too weak to run any single PCIe video card. You MUST upgrade to a minimum of 450w with at least 18a on the +12v line (preferably two or more +12v lines or "rails" as they're called these days). 150w will just not work. If the PC even powers on correctly, you'll be plagued with constant lock ups, crashes, erratic behavior, etc. If you want to run dual cards in SLI, then I'd say a minimum 600w high end PSU is required. As to the PCIe 2.0 and 1.0.... you can run a PCIe2.0 card in a 1.0 motherboard without any loss in video performance. From what I've read, the 2.0 standard is still in its infancy and hasn't been fully developed to its true potential yet, even in 2.0 compliant motherboards, so I wouldn't worry about it too much just yet.

But, be sure to upgrade that power supply before you buy any video card. Your current unit is just way too weak. And don't be cheap when buying a PSU. A $40 600w power supply, and a $125 600w power supply are not equal. Even if they both have dual rails with 20a per rail, the cheap one is just that: cheap, and likely has a shorter warranty; 90 days to one year is common with cheap PSUs, while the higher end name brand units typically have at least 3 years. Many people have no problem shelling out $200 for a video card, $100 for RAM, another $200 for a CPU, but they balk at spending $100 or more on a quality power supply. When you consider what the power supply does, and just how important it is to have a high quality unit, you'll then realize that the power supply is probably the most important component in a PC, and skimping on it and buying a cheap unit is doing your PC (and yourself) a huge dis-service.

[dlb]

 

I'm sorry, I was careless and made a mistake in my first post. My psu is 450 watts, not 150 watts. I apologize for the confusion.

That's good news about the video card. I wanted to do a minor upgrade now and maybe, in a year or so, do a full upgrade with another motherboard, cpu, psu, etc. I was thinking of going with a 9600 gt.