3870XT - PCi-e 4x?

[denic]

Hello guys.

I want to buy a 3870 XT Extreme 512MB but the problem is that my motherboard is only 4X Pci-e. Will this card work with 4x Pci-e?

If it will work, will I be loosing alot of performance?

I currently have an X1950 Pro AGP 8X, but if the 3870XT will beat it at 4X I will upgrade.

Thanks.

 

[cnumartyr]

You have an AGP 8x/4x and PCIe 4x slot on the same mobo?

It might work, but it would be seriously bandwidth limited.

 

[aevm]

Yes, running in an x4 slot will hurt performance a lot. There was a great article on this subject on Tom's some months ago.

How about buying a $100 GA-P35-DS3L motherboard along with the HD 3870?

Another possible solution is to get an AGP version of the HD 3850. It's supposed to show up soon.

Edit: just to clarify, the first solution, buying a P35 motherboard and sticking with PCI-E video, is much smarter, even if it costs more.

 

[denic]

Thanks for your replys.

If any one could answer my actual question that would be great.

At 4x would the card beat an x1950 pro?

cheers

 

[blade85]

yes it would beat the x1950 pro...by a good margine....but it wont be anywhere near as good as it can get on a 16x board.

 

[Evilonigiri]

Which is why we suggest getting a new motherboard.

 

[blade85]

by the way, here is an article at toms u might wanna have a look at.

http://www.tomshardware.co.uk/PCI-Express-2-0-Crossfire,review-29948.html

it starts off with pci-e 2.0 but also shows performance loss on pci-e when going from 16x to 8x and then to 4x

 

[denic]

Thanks for your replys.

Well as long as it will beat the X1950 I'm happy.

I can't get a new motherboard as I can't afford one - I'm on a budget.

 

[cnumartyr]

Thanks for your replys.

Well as long as it will beat the X1950 I'm happy.

I can't get a new motherboard as I can't afford one - I'm on a budget.

I would budget a new motherboard + HD3850.

 

[denic]

I wouldn't be able to get a new motherboard and a 3870 for £160 though.

 

[nachowarrior]

errr...
have any of you seen some of the performance tests where they actually take a 16x card and 16x mobo and tape it off one at a time... the HIGHEST they tested was only using 4x. that may not be the same case now... but i doubt it'll be that massive of a difference.

 

[cnumartyr]

errr...
have any of you seen some of the performance tests where they actually take a 16x card and 16x mobo and tape it off one at a time... the HIGHEST they tested was only using 4x. that may not be the same case now... but i doubt it'll be that massive of a difference.

So.... PCIe2.0 2x = PCIe1.0 4x... I really think you would be bandwidth limiting the card (this generation atleast).

Also to the OP: I said an HD3850, not 3870.

 

[denic]

That would still be out of budget I think.

 

[denic]

Hello again.

I've had a read around and got these.

http://www.overclockers.co.uk/showproduct.php?prodid=MB-003-OK&tool=3
http://www.overclockers.co.uk/showproduct.php?prodid=GX-084-OK.

What do you think about these? This is about the max my budget can go!

Cheers.

 

[nachowarrior]

there is still overhead left over, otherwise they couldn't make fast cards or better games without having to go with another slot... kind of makes me wonder why people will buy 2 graphics cards and put them in "sli" or "crossfire" when you can get better performance from what you spent on the 2x cards (unless you buy the fastest single card on the market at the time, which means you have too much money anyway) and even then... as long as there is bigger games and a faster card coming out.... then it means the bandwidth to/from the mobo is not being completely used.

 

[cnumartyr]

there is still overhead left over, otherwise they couldn't make fast cards or better games without having to go with another slot... kind of makes me wonder why people will buy 2 graphics cards and put them in "sli" or "crossfire" when you can get better performance from what you spent on the 2x cards (unless you buy the fastest single card on the market at the time, which means you have too much money anyway) and even then... as long as there is bigger games and a faster card coming out.... then it means the bandwidth to/from the mobo is not being completely used.

There isn't overhead.. the HD3870 is a PCIe2.0 card, not PCIe1.0. It won't max out a 16x PCIe1.0 slot, but it probably will come close to maxing 8x if not more.

 

[Evilonigiri]

There isn't overhead.. the HD3870 is a PCIe2.0 card, not PCIe1.0. It won't max out a 16x PCIe1.0 slot, but it probably will come close to maxing 8x if not more.

Couldn't you just increase the PCIe frequency to increase bandwidth?

100MHz --> 120MHz

 

[cnumartyr]

Couldn't you just increase the PCIe frequency to increase bandwidth?

100MHz --> 120MHz

Yea, but (and I can't remember the link) on some boards increasing PCIe Freq over 115 MHz can cause issues with the SATA ports.

100 MHz -> 120 MHz = 20% increase.

500 MB/s per slot up/down. 600 MB/s from the overclock.

2.4 GB/s Up/down 4x
9.6 GB/s Up/down 16x
8 GB/s Up/down 16x Normal

 

[Evilonigiri]

Yea, but (and I can't remember the link) on some boards increasing PCIe Freq over 115 MHz can cause issues with the SATA ports.

So I've read.

MSI's site states that they won't guarantee anything over 120MHz.

 

[denic]

Can anyone give me some information on the 2 parts I'm planning on buying please?

 

[Evilonigiri]

The second link doesn't go to any particular item.

 

[denic]

Damn it, I'm terrible lol.

The 2nd link is http://www.overclockers.co.uk/showproduct.php?prodid=GX-084-OK

 

[Evilonigiri]

Just by looking at the specs, the motherboard looks fine. You should do further research though.

The HD3850 256MB is a good video card, in fact, it's the best valued out there right now. I'm not sure about the brand, but as long as you trust them it's also fine.

 

[denic]

Just by looking at the specs, the motherboard looks fine. You should do further research though.

The HD3850 256MB is a good video card, in fact, it's the best valued out there right now. I'm not sure about the brand, but as long as you trust them it's also fine.

Thanks for your advice.

As for the brand I assume 'OcUK' is the brand? Haven't really used any of there branded stuff but I aren't too fussed really.

 

[Zen911]

hi there..
I have a gigabyte 945gz mobo .. and i'm not quite sure if it has a 16x pci-e or not .... I look at the manual and only pci-e is written there while in some other cases like the 945pl pci-e 16x is written .. does this mean that i don't have a 16X ??? need help please