Tom's Hardware > Forum > Graphic & Displays > Graphics Cards > How much will PCIe 4x affect performance?

How much will PCIe 4x affect performance?

Forum Graphic & Displays : Graphics Cards - How much will PCIe 4x affect performance?

Tom's Hardware: Over 1.4 million members in 6 different countries available to answer all your high-tech questions. Sign up now! Its free!
Ask the community Add a reply
Word :    Username :           
 
ghostwalker   10-16-2007 at 02:38:19 PM

Basically I'm looking to upgrade my aging Geforce 7600GT AGP to a Geforce 8800GT, when they come out. One thing I wondered about though is that my current motherboard, Asrock 775dual-VSTA, only has a PCIe 4x slot and I just wondered if/how much this would bottleneck something like a 8800GT.

Thanks.

Rig -

Asrock 775dual-VSTA
Core2Duo E6600
Enermax EG365AX 350W PSU
1.5Gb DDR RAM *(soon to be 2Gb DDRII)
500Gb HDD
Geforce 7600GT

Add a reply
Sponsored Links
Register or log in to remove.
toasty2   10-16-2007 at 02:42:21 PM
- 0 +

I heard that it wasn't a big deal, since cards don't use all the bandwidth (that was for x8 though, not sure about x4).

------------------------------ Gigabyte GA P35 DS3L | Intel E5200 @ 3Ghz w/ AC Freezer 7 Pro | 6GB DDR2-800 | Gigabyte 8800GT w/ Zalman VF700 | Silverstone 500W
 Reply to toasty2
wingsofzion   10-16-2007 at 02:43:53 PM
- 0 +

most likely it'll just down clock to 4x


Message edited by wingsofzion on 10-16-2007 at 02:45:58 PM
Reply to wingsofzion
Wolfshadw   10-16-2007 at 02:54:51 PM
- 0 +

http://www.tomshardware.com/2007/0 [...] _analysis/

Read through this.

-Wolf sends

Message quoted 1 times
------------------------------ System Specs:
Gigabyte EP43-UD3L Intel Core2Quad Q8400 8 Gig RAM
NVidia Geforce 8800GTS-640/Creative X-FI Extreme Music/Dual-Boot XP-64&Server2008
 Reply to Wolfshadw
aevm   10-16-2007 at 03:58:04 PM
- 0 +

So, it may work at 1/4 of its capacity (i.e. even fewer fps than the 7600 GT), or it may work at almost full capacity, depending on the game. I think it's time for a new motherboard. Something like GA-P35-DS3L, maybe?

I think you'll need a new PSU too.

Reply to aevm
zenmaster   10-16-2007 at 04:04:30 PM
- 0 +

According to the article, you will definitely need a new motherboard.
The 8800GTS is severely limited by the 4x PCIE. The 8800GT which is rumored to be faster will definitely deliver well under 1/2 its possible performance.

The GPU may be borderline, we will need to see.
The 8800GT is supposed to use less power than the 8800GTS so we will just need to see how much less.

Reply to zenmaster
ghostwalker   10-16-2007 at 04:06:25 PM
- 0 +

Wolfshadw wrote :

http://www.tomshardware.com/2007/0 [...] _analysis/

Read through this.

-Wolf sends



Thanks Wolf. Very useful.

So basically it makes a very big difference. Now my only problem left is to decide whether I should just suck it up, buy the card and put up with the loss in performance, buy a new motherboard, or buy a Radeon X1950 and stick it out with AGP for a little longer...mmm...

Reply to ghostwalker
blade85   10-16-2007 at 04:08:51 PM
- 0 +

Thos graphs do however put up some further questions.

 

Since only the 8800 and the x1900's were used, it could mean one of a few things:

 

1- The Nvidia cards are affected more than the ATI ones (since we have no data on the 2900's performance at 4x pci-e and also since we dont have any data on how the 7900 cards run at 4x pci-e)

 

2- It affects new gen high end cards a lot more irrespective of make (since they need more bandwith than can be supplied by a 4x pci-e slot )

 

Someone needs to take a bigger range of cards and run them through the different slots cause just using a 8800 and a x1900 doesnt seem good enough to me.

 

I would have liked to see 1900, 1950, 7800, 7900, 8800, and 2900 in there.

 


Message edited by blade85 on 10-16-2007 at 04:10:41 PM
------------------------------ I came here to kick ass and chew bubblegum.....and I'm all out of gum!
 Reply to blade85
KyleSTL   10-16-2007 at 04:18:14 PM
- 0 +

To put it this way: a 7600GT is probably limited at a AGP4x bandwidth (1067 MB/s) and PCIe 4x runs at 1000 MB/s. Your 8800GT in that interface would be trying to suck a bullfrog through a garden hose. So going from a AGP 8x to a PCIe 4x is a very bad idea. All this information is available on Wikipedia under the title "List of Device Bandwidths".

------------------------------ Lian-Li PC-7B | XClio Greatpower 550W | P4 3.2 Prescott SL7E5 | Scythe Ninja
2GB DDR400 Corsair VS (4*512) | eVGA nVidia GF 7600GS AGP vmod 1.46/1.91 OCd 759/907
WD 160GB & 640GB SATA
WinXP MCE 2004
 Reply to KyleSTL
ghostwalker   10-16-2007 at 04:21:36 PM
- 0 +

Mmm...looks like I may have to go for the new m/b and psu then if I want to upgrade the gpu. Mmm...this could prove expensive.

Reply to ghostwalker
aevm   10-16-2007 at 05:11:11 PM
- 0 +

But it will be a MUCH better machine :)

Just wondering, does anybody know how big the 8800 GT will be? Will it be as big as the GTX, forcing some people to upgrade their cases too?

Reply to aevm
Hatman   10-16-2007 at 05:30:37 PM
- 0 +

9 inches long and single slot, that much about it is 100% confirmed lol

(dont flame me again :D )

------------------------------ Na na na na na na na na HATMAN!
 Reply to Hatman
Ask the community Add a reply
Tom's Hardware > Forum > Graphic & Displays > Graphics Cards > How much will PCIe 4x affect performance?
Go to:

There are 1087 identified and unidentified users. To see the list of identified users, Click here.

Forum map
Bestofmedia Forum ©
2000-2009 Bestofmedia Group
Page generated in 0.305 seconds
Please mind

You are about to answer a thread that has been inactive for more than 6 months.
If you still wish to proceed, please ensure that your posting is original and does not duplicate or overlap any prior responses to this thread.

Add a reply Cancel
Sponsored links
  • Ask the community now
  • Publish
Ad
Related Topics
See all relatives topics
They won a badge
Join us in greeting them