Pcie Conflict

Post by **Dangerous Bob** » Thu Jan 09, 2014 6:47 pm

Am I right in thinking that a PCIe 2.1 card will not work in a PCIe v1.0 board?

Post by **madman045** » Thu Jan 09, 2014 7:20 pm

Hi Bob,

Yes it should work, just has less bandwidth available to the card

Can you provide us more details on your system, motherboard model and PSU model?

Andy

Post by **Dangerous Bob** » Thu Jan 09, 2014 11:18 pm

KN8SLI mobo with a 500/650W PSU (Atrix 500T)
Trying to put a HD5850 into it, The PSU was powering the card in another PC before.

The system works fine with an old PCIe card I've got, but I don't even get a POST beep with the 5850.
Everything spins up and lights up OK.

Post by **madman045** » Fri Jan 10, 2014 1:21 am

wow that's a blast from the past, what bios does the board currently have?

Post by **Hammer** » Fri Jan 10, 2014 6:38 am

It should work, but there are boards that don't work with newer cards (old Nvidia chipset boards have this issue).

Post by **Dangerous Bob** » Fri Jan 10, 2014 8:39 am

will see f the BIOS needs flashing, though It's probably done, Used to be quite keen on that sort of thing when it was the main PC a few years back...

Post by **Claw** » Fri Jan 10, 2014 10:25 am

I've heard of backwards compatibility issues with some PCIE 2 cards with PCIE 1 Mobo's, but it isn't a blanket issue. If your BIOS is at the latest firmware, then double checking and reseating connectors then clearing the CMOS may be just enough straws to clutch at. Don't just set BIOS defaults from within the BIOS, do a proper CMOS clear with the jumper, etc. Hopefully this will be enough to make your Mobo think twice about messing with Dangerous Bob...

Gonna do a bit more background on the backwards compatibility of this vid card with PCIE 1... Usually, if a card has this kind of compatibility issue it is plainly stated somewhere, but I haven't seen this said anywhere yet.

Edit: Just to add something about PSU requirements, AMD say regarding the power requirements for this vid card are... <div class='quotetop'>QUOTE</div><div class='quotemain'>500 Watt or greater power supply with two 75W 6-pin PCI ExpressÂ® power connectors recommended (600 Watt and four 6-pin connectors for ATI CrossFireXâ„¢ technology in dual mode). </div>

Post by **Dangerous Bob** » Fri Jan 10, 2014 12:10 pm

I reset CMOS and reseated everything, It's definitely card related.

I'll try another PSU, but as I said, this PSU was what was powering it before and this time it's only got 1 HD to power on a lesser board rather than the 4 HDs + USB stuff + PCI bits + DVD etc.
Might just swap the plugs and extension leads about to see if that's the issue...

Post by **Claw** » Fri Jan 10, 2014 10:36 pm

What I've read here and there is that...

PCIe is backwards compatible if the latest firmware accommodates it. The 5850 is PCIe 2.1, but there is talk out there that suggests the HD5850 is a tad pernickety with PCIe 1.1 and backwards. I've not seen this in any of AMD's references to confirm this though.

The HD 5850 requires 500-700 Watt PSU pushing 35-40 Amps on the +12 Rails. It looks like your 500T PSU is only pushing just over 30 Amps.

Try connecting to your display with each of the card's connectors. Although if it was anything to do with this you would notice a lot of ongoing activity despite no display.

These are the only possible causes I could find that may be behind your issue here. It would be good to get this sorted before any gaming withdrawal symptoms kick in.

Post by **Dangerous Bob** » Sat Jan 11, 2014 9:50 am

NO probs with gaming withdrawal.

In my main PC I've chucked the 6970 I've just bought. Get a whole extra 5fps playing DAYZ Epoch, but thats Dayz for you,....
I also took the Atrix PSU out at this point with the 5850 and replaced it with a bigger 600w PSU.
I'm also mining at 470kh/s but thats with the temps and fans going at reasonable levels. Could get over 500, but it's way too loud to be in the same room as.

Anyway, just thought I'd revive an old PC I've got under the desk that had an EAX800T, then chug it off mining with remote access...
Stuck the Atrix PSU in as I knew it could power the 5850 in the other machine.
funnily enough, if I swap the shadow card and GFX around, the mobo will POST, but I get no display...

So first thing might be to try another PSU, maybe temporarily transfer the new one across...

I have put the old EAX in and tried to check what BIOS it's has, but the PC boots, but then shuts down after a minute or two, so got to go through fault finding that first. Could be the PSU has let go after all anyway...

Love this stuff.....

Post by **Dangerous Bob** » Sun Jan 12, 2014 7:34 pm

OK tried new PSU, flashing the BIOS and even putting another PCIe card in the first slot and the 5850 in the second, but it looks like the card just does not like the KN8SLI board...

I've got hold of another board to try next week, an MSI MS-7168 Ver: 2.0 Socket 939, which hopefully will work.

Post by **Hammer** » Mon Jan 13, 2014 7:21 am

Hammer wrote: It should work, but there are boards that don't work with newer cards (old Nvidia chipset boards have this issue).

Your board runs the Nvidia chipset doesn't it?

Post by **Dangerous Bob** » Mon Jan 13, 2014 10:09 am

the KN8SLI?

think so, certainly SLI is all about Nvidia.

You reckon it's sulking beacause I'm putting yet another AMD card in it?

Don't think I've ever had an Nvidia one...