Crossfire capable motherboard and single GPU slot compatibility

[agent031693]

Just bought an Asus Q87M-E, on eBay for $36. Supposedly came from a working machine. Purpose for buying it was to crossfire my RX 580 later this month or early this year. So far I found that one of it's 4 dimms and the built in HDMI plug are broken. Everything else, so far seems to be okay. (Well also might have 3 broken temperature gauges - out of 6, 3 show temps around 30°c, while the last 3 show temps above 100°c).

The question: If I don't have a 2nd RX 580 right now, how can I test it's 2nd PCIE 8x lane? My first guess is to take the GPU out of the 16x lane and plug it in there. Should a GPU (specifically the RX 580 - otherwise I have a GTX 750 ti) be able to run on an 8x lane alone? Or will that extra PCIE only work when I have a 2nd GPU plugged in there?

 

[AnonymousAndy]

Just bought an Asus Q87M-E, on eBay for $36. Supposedly came from a working machine. Purpose for buying it was to crossfire my RX 580 later this month or early this year. So far I found that one of it's 4 dimms and the built in HDMI plug are broken. Everything else, so far seems to be okay. (Well also might have 3 broken temperature gauges - out of 6, 3 show temps around 30°c, while the last 3 show temps above 100°c).

The question: If I don't have a 2nd RX 580 right now, how can I test it's 2nd PCIE 8x lane? My first guess is to take the GPU out of the 16x lane and plug it in there. Should a GPU (specifically the RX 580 - otherwise I have a GTX 750 ti) be able to run on an 8x lane alone? Or will that extra PCIE only work when I have a 2nd GPU plugged in there?

Your 16x card will fit in your 2nd 16x slot, it will work fine in that slot. You can't plug in your 580 to the standard PCI slots which I'm assuming you're referencing to when you say 8x. Your 2nd 16x slot says (x4 mode), due to lack of interest I didn't research further, but I'd assume that this means your 2nd slot will not support full 16x bandwidth. This means your 16x GPU will fit and it will work, but it will suffer a performance hit in some way.

 

[agent031693]

Just bought an Asus Q87M-E, on eBay for $36. Supposedly came from a working machine. Purpose for buying it was to crossfire my RX 580 later this month or early this year. So far I found that one of it's 4 dimms and the built in HDMI plug are broken. Everything else, so far seems to be okay. (Well also might have 3 broken temperature gauges - out of 6, 3 show temps around 30°c, while the last 3 show temps above 100°c).

The question: If I don't have a 2nd RX 580 right now, how can I test it's 2nd PCIE 8x lane? My first guess is to take the GPU out of the 16x lane and plug it in there. Should a GPU (specifically the RX 580 - otherwise I have a GTX 750 ti) be able to run on an 8x lane alone? Or will that extra PCIE only work when I have a 2nd GPU plugged in there?

Your 16x card will fit in your 2nd 16x slot, it will work fine in that slot. You can't plug in your 580 to the standard PCI slots which I'm assuming you're referencing to when you say 8x. Your 2nd 16x slot says (x4 mode), due to lack of interest I didn't research further, but I'd assume that this means your 2nd slot will not support full 16x bandwidth. This means your 16x GPU will fit and it will work, but it will suffer a performance hit in some way.

Yes. It doesn't support full bandwidth. I just wanted to know if it should work in there. Haven't tried plugging it in there. But if it doesn't work, I will be returning the MoBo. Thanks