PCI-E and AGP Speed differences

[bl4ckfl4g]

I have a nice for incremental upgading but definately not a high performance mobo.

Asrock 775 Dual VSTA.

It supports AGP(8x) and PCIE(4x).


I want to upgrade from a x1300 AGP to a 7900GS PCI-E. How much will the 4x PCI-E slot bottleneck the card? Would I be better off getting an AGP version if I can find one?

I won't be able to upgrade the mobo any time soon plus it actually runs pretty good and is very stable. It just sucks that the PCI-E bus is so slow.

 

[Tarrant64]

Unless you're a hardcore gamer I don't think you have to worry about bottlenecks. I thought the main argument concerning that was processor vs. GPU, not GPU vs. motherboard. Although I could be wrong.

In either case I think the 7900GS would be a decent performance increase regardless. What processor are you currently running?

 

[bl4ckfl4g]

Currently
Pentium D 820 Smithfield 2.8ghz.
2x 512mb OCZ DDR 400


I am going to incrementaly upgrade each piece until I have pci-e video, ddr2 ram, c2d then I'll grab a better mobo. With a kid coming in June though it is gonna take a little bit. My current bottleneck seems the vid card. The only game I run that seems to do in my processor is Supreme Commander and even that is alot more playable than I've seen some people talk about.

 

[happy medium]

Thats a good upgrade 4x pci-e won't bottleneck with a 7900gs. You could just get a 1950xt AGP when they come out. The 1950 pro is AGP too which is faster then the 7900gs.

 

[Tarrant64]

Originally posted by: happy medium
Thats a good upgrade 4x pci-e won't bottleneck with a 7900gs. You could just get a 1950xt AGP when they come out. The 1950 pro is AGP too which is faster then the 7900gs.

Probably a better deal actually.

If you plan to stick to AGP for awhile go this route. Otherwise PCI-E will allow you to upgrade the CPU/Motherboard later without having to go through getting a new GPU.

So the choice comes down to what you want to do.

 

[bl4ckfl4g]

Originally posted by: happy medium
Thats a good upgrade 4x pci-e won't bottleneck with a 7900gs. You could just get a 1950xt AGP when they come out. The 1950 pro is AGP too which is faster then the 7900gs.

Cool thanks. I think the limiting factor right now is price. I want a decent upgrade on the cheap because I will upgrade to a DX10 whenever vista sp1 comes out.

I think the 7900GS is quite a bit cheaper than the X1950s that I saw. Even though I usually buy ATI.

 

[bl4ckfl4g]

Originally posted by: Tarrant64

Originally posted by: happy medium
Thats a good upgrade 4x pci-e won't bottleneck with a 7900gs. You could just get a 1950xt AGP when they come out. The 1950 pro is AGP too which is faster then the 7900gs.

Probably a better deal actually.

If you plan to stick to AGP for awhile go this route. Otherwise PCI-E will allow you to upgrade the CPU/Motherboard later without having to go through getting a new GPU.

So the choice comes down to what you want to do.

Ya I'd prefer to get a PCIE if it won't run too crappy at 4x.

 

[zephyrprime]

I think this is a moot point because I believe the 775dual vsta has a 16x pcie connector

http://www.asrock.com/mb/overview.asp?Model=775Dual-VSTA&s=n

 

[bl4ckfl4g]

Nah unfortunately the pci-e slot is only 4x.

 

[mike420]

I am with Tarrant64. If your mobo really is limited, you will want to upgrade that part at a later date so why sink money into an AGP card? PCIe sounds like the better route to me.
2 cents..

 

[bl4ckfl4g]

Originally posted by: mike420
I am with Tarrant64. If your mobo really is limited, you will want to upgrade that part at a later date so why sink money into an AGP card? PCIe sounds like the better route to me.
2 cents..

Yeah that's what I want to do. I just want to make sure the jump from X1300 (agp 8x) to 7900GS(4x PCI-E) is worth it. Thanks.

 

[Tarrant64]

I was reviewing the posts and saw you had mentioned DX10. I think the 8800 series is the only one with that support at the moment. With Vista SP1 is there going to be DX10 support for mid-range cards or what?

Why I'm asking is because if you buy the 7900 now, you will still have to upgrade your PCI card later to have the ability to use DX10.

 

[chizow]

In some of the more recent ports like the 7800GS and X1950pro there's very little difference between the AGP and PCI-E part performance. Not sure what the bandwidth numbers are between the two or how much difference there is between the PCI-E speeds, but there have been a few reviews and user reports of poor performance running PCI-E at 2x and 4x on faster cards like the 8800s. The AT review of the Gateway QX6700 indicate the 8800GTX takes a performance hit running at 4x, although the comparison isn't perfect since the testbeds are slightly different.

 

[bl4ckfl4g]

I will definately need to buy another card to use DX10 but I'm thinking that I will wait at lest 7 or 8 months.

I may want to upgrade my mobo before that but I won't be able to if I have an AGP card. That is the only reason I want to get a PCIE now.

 

[Tarrant64]

Sounds good enought o me.

 

[bl4ckfl4g]

Originally posted by: chizow
In some of the more recent ports like the 7800GS and X1950pro there's very little difference between the AGP and PCI-E part performance. Not sure what the bandwidth numbers are between the two or how much difference there is between the PCI-E speeds, but there have been a few reviews and user reports of poor performance running PCI-E at 2x and 4x on faster cards like the 8800s. The AT review of the Gateway QX6700 indicate the 8800GTX takes a performance hit running at 4x, although the comparison isn't perfect since the testbeds are slightly different.

Alright thanks. I'll look around to see if I can find anything about performance hits running a 7900gs at 4x.


Thanks again for your help guys.

 

[mike420]

Happy hunting!

 

[happy medium]

Here ya go pci-e x4 vs agp x8, but its with a 6800ultra.

http://www.anandtech.com/mb/showdoc.aspx?i=2814&p=4