Sapphire R9 280X No video output/Crossfire

[TheVoiceofExile]

Sorry for the terrible thread title but I couldn't think of anything else.

 

I have a deal I can take for a Sapphire R9 280X Dual-X graphics card that doesn't provide any video out for 40 dollars. I'm not sure if I should take it or not. I have a 7950 (OC'D to to the same clocks as 7970) currently and I know the 280X is a rebrand so I can crossfire them together. However I'm not sure if the crossfire will work still with the second card not providing output. I'd use my 7950 as the main card since I'll use that for my video output (obv the other doesn't work can't use that), so I'll lose some performance in that regard but I don't really care about that.

 

What I want to know is even with the 280X not providing video out (but still fully functioning according to the seller), can I successfully crossfire that 280X with my 7950? Links to both cards below:

 

280X: http://www.newegg.com/Product/Product.aspx?Item=9SIA57522E5282&cm_re=r9_280x_sapphire_dual-x-_-9SIA57522E5282-_-Product

7950: http://www.newegg.com/Product/Product.aspx?Item=N82E16814127733&cm_re=msi_7950-_-14-127-733-_-Product

[Kermit]

If it can't connect to the other card via Xfire and can't be used as a single card, its basically a brick. Thats why its $40.

 

Edit: How does the seller know that it is still functional if it can't display anything to a screen?

[Raudi_]

Sorry for the terrible thread title but I couldn't think of anything else.

 

I have a deal I can take for a Sapphire R9 280X Dual-X graphics card that doesn't provide any video out for 40 dollars. I'm not sure if I should take it or not. I have a 7950 (OC'D to to the same clocks as 7970) currently and I know the 280X is a rebrand so I can crossfire them together. However I'm not sure if the crossfire will work still with the second card not providing output. I'd use my 7950 as the main card since I'll use that for my video output (obv the other doesn't work can't use that), so I'll lose some performance in that regard but I don't really care about that.

 

What I want to know is even with the 280X not providing video out (but still fully functioning according to the seller), can I successfully crossfire that 280X with my 7950? Links to both cards below:

 

280X: http://www.newegg.com/Product/Product.aspx?Item=9SIA57522E5282&cm_re=r9_280x_sapphire_dual-x-_-9SIA57522E5282-_-Product

7950: http://www.newegg.com/Product/Product.aspx?Item=N82E16814127733&cm_re=msi_7950-_-14-127-733-_-Product

You won't be able to crossfire them only the 7970 can be crossfired with the 280x. 

So this wouldn't be a very good deal unless you get the 280x working.

[arnavvr]

You won't be able to crossfire them only the 7970 can be crossfired with the 280x. 

So this wouldn't be a very good deal unless you get the 280x working.

 

It will work since 7950's and 7970 can CF

[Raudi_]

It will work since 7950's and 7970 can CF

Actually with the R9 series cards and the 7000 series cards its different. 

I have tried myself with a 7970 and the R9 280 i have now. It doesn't work

[arnavvr]

 Yes you can http://www.tomshardware.com/forum/id-1842970/280x-7950-crossfire.html

[TheVoiceofExile]

Yeah from everything I've read the 280 and 280X are just rebranded 7950s and 7970s. I'm also pretty sure the 7950 and 7970 use the same chip just at different clocks.

[TheVoiceofExile]

If it can't connect to the other card via Xfire and can't be used as a single card, its basically a brick. Thats why its $40.

 

Edit: How does the seller know that it is still functional if it can't display anything to a screen?

I'm not 100% sure, I'm asking him now about how he determined it's still functioning.

[Kermit]

I'm not 100% sure, I'm asking him now about how he determined it's still functioning.

 

sweet. imo, if it cant xfire or output its not worth $40

[-rascal-]

Yeah from everything I've read the 280 and 280X are just rebranded 7950s and 7970s. I'm also pretty sure the 7950 and 7970 use the same chip just at different clocks.

The HD 7950 (280) is a cut down version of the HD 7979 (280X); is has fewer processing cores, ROP's, etc.

They use the same 'Tahiti' chip under hood, though.

If for what ever, reason, it's just the display output that is dead (see if the seller can try the DisplayPort...since it uses a different internal clock than the DVI and HDMI ports), then you should he able to hook it up in Crossfire.

Otherwise, if a more critical section of the card is damaged, then it is completely useless.

[TheVoiceofExile]

sweet. imo, if it cant xfire or output its not worth $40

 

 

The HD 7950 (280) is a cut down version of the HD 7979 (280X); is has fewer processing cores, ROP's, etc.

They use the same 'Tahiti' chip under hood, though.

If for what ever, reason, it's just the display output that is dead (see if the seller can try the DisplayPort...since it uses a different internal clock than the DVI and HDMI ports), then you should he able to hook it up in Crossfire.

Otherwise, if a more critical section of the card is damaged, then it is completely useless.

Great news. Not only did he only charge me 20 bucks for the 280X, but it is 100% FULLY FUNCTIONING AND ALL THE PORTS WORK. Literally everything about it works and it benchmarks nearly identically to my OC'D 7950 (Who would have guessed, hehe). It is missing a screw from the back of the GPU cooler mounting bracket though (one of the 4 that hold it on the GPU itself) but I plan on getting a screw to replace it. Presumably because of the missing screw temps are higher than they should be, idling around 43*C instead of the 30*C my other card idles at (with 1 GPU installed). When I get home I'm going to replace the screw and remount the GPU cooler on the new card.

 

A follow up question however, which card should I use as my main card in the crossfire configuration? I can clock them both to the same exact GPU and Memory speeds (I have the golden egg of a 7950s) and I assume that would mean either can be the main card (the one connected to my displays) without a performance loss. Which do you guys think I should make the main card in that situation?

 

Also what, if any, performance degradation would I experience having both cards running in PCI-E 4x slots? My sound card is PCI only and that PCI slot also happens to block my other 16x PCI-E socket from accepting a dual slot card. Meaning either ditch the sound card or have the config run in 4x 4x. If there aren't any downsides to that then great I'm 100% okay with it, otherwise do I have any options in that regard?

[TheVoiceofExile]

Great news. Not only did he only charge me 20 bucks for the 280X, but it is 100% FULLY FUNCTIONING AND ALL THE PORTS WORK. Literally everything about it works and it benchmarks nearly identically to my OC'D 7950 (Who would have guessed, hehe). It is missing a screw from the back of the GPU cooler mounting bracket though (one of the 4 that hold it on the GPU itself) but I plan on getting a screw to replace it. Presumably because of the missing screw temps are higher than they should be, idling around 43*C instead of the 30*C my other card idles at (with 1 GPU installed). When I get home I'm going to replace the screw and remount the GPU cooler on the new card.

 

A follow up question however, which card should I use as my main card in the crossfire configuration? I can clock them both to the same exact GPU and Memory speeds (I have the golden egg of a 7950s) and I assume that would mean either can be the main card (the one connected to my displays) without a performance loss. Which do you guys think I should make the main card in that situation?

 

Also what, if any, performance degradation would I experience having both cards running in PCI-E 4x slots? My sound card is PCI only and that PCI slot also happens to block my other 16x PCI-E socket from accepting a dual slot card. Meaning either ditch the sound card or have the config run in 4x 4x. If there aren't any downsides to that then great I'm 100% okay with it, otherwise do I have any options in that regard?

So I ordered a ribbon extender for my PC slot that I'm going to use to move my sound card out of the way and a crossfire bridge that I'm considering sleeving blue. Everything is going to be great now, although I'd still like to know what card should be my main card.

[dragoon20005]

So I ordered a ribbon extender for my PC slot that I'm going to use to move my sound card out of the way and a crossfire bridge that I'm considering sleeving blue. Everything is going to be great now, although I'd still like to know what card should be my main card.

the 280X will be the main card

 

so when you are unable to use CF

 

the 280X will be the more powerful GPU in the link

[Kermit]

damn dude thats a sweet deal lol

 

craigslist?

[Blackie Sheen]

you cant crossfire those. They dont have the same number of stream processors. the r9 280x(7970 gHz edition) has 2048 stream processors and the 7950 has 1792. They are not the same gpu hence not crossfire compatible

[SkilledRebuilds]

you cant crossfire those. They dont have the same number of stream processors. the r9 280x(7970 gHz edition) has 2048 stream processors and the 7950 has 1792. They are not the same gpu hence not crossfire compatible

Yes they can, it's been done MANY times before. Read the links provided in the above posts.

7970 and 7950 has been done before, 280X and 280 has been done before,.. and likewise the rebrands can be done with the non-rebrands of the similar chips.

Read the comments of this thread - Not the OP as he has other issues http://www.reddit.com/r/buildapc/comments/2hk9nz/just_installed_an_r9_280x_to_crossfire_with_my_hd/

It's done by many users.

[-rascal-]

you cant crossfire those. They dont have the same number of stream processors. the r9 280x(7970 gHz edition) has 2048 stream processors and the 7950 has 1792. They are not the same gpu hence not crossfire compatible

AMD drivers are much more flexible than nVidia.

I have a HD 7950 Vapor-X in my second system. If you want, I can swap it out with one of my HD 7970's and run a HD 7970 + 7950 Crossfire, and post a few pictures...

From AMD's website:

[TheVoiceofExile]

damn dude thats a sweet deal lol

 

craigslist?

Yeah, someone was selling it through my University's craiglist facebook page. He also had a Corsair H60 for 10 bucks but my air cooler totally beats it in benchmarks so I didn't bother.

[TheVoiceofExile]

the 280X will be the main card

 

so when you are unable to use CF

 

the 280X will be the more powerful GPU in the link

So I have a bit of a predicament....my PCI slots go in the following order:

 

PCI-E 1x

PCI-E 16x (GPU 1)

PCI-E 4x (Covered by GPU1)

PCI-E 16x

Standard PCI (Populated by sound card)

PCI-E 4x

(All 2.0 slots)

 

Ideally as understand it I would want to use the PCI-E 16x slots for the graphics cards. The problem with this is that the PCI slot will be ran over by the second GPU whenever I add it, which means I can't use my sound card anymore. Well I kind of like my sound card (unless someone wants to trade/send me an DAC/AMP combo or something) and would rather not lose it. This brings my options down to installing the 2nd GPU in the PCI-E 4x slot. Since crossfire is limited by the weakest GPU, the 4x slot will bring my 16x slot down to 4x as well. Being newer to multi-card setups I don't know what kind of performance impact this is going to have.

 

I have a PCI slot ribbon extender on the way with my crossfire bridge to hopefully work around this, but since both cards have aftermarket coolers on them I'm worried about clearance with the cooler and the ribbon extender. If it works then all will be well but I wanted to start brainstorming backup plans in case it doesn't go as I intend it to.

 

What do you think would be the best way to work around this slot problem? Is the performance impact of the PCI-E 4x slot minimal enough to just ignore?

[dragoon20005]

So I have a bit of a predicament....my PCI slots go in the following order:

 

PCI-E 1x

PCI-E 16x (GPU 1)

PCI-E 4x (Covered by GPU1)

PCI-E 16x

Standard PCI (Populated by sound card)

PCI-E 4x

(All 2.0 slots)

 

Ideally as understand it I would want to use the PCI-E 16x slots for the graphics cards. The problem with this is that the PCI slot will be ran over by the second GPU whenever I add it, which means I can't use my sound card anymore. Well I kind of like my sound card (unless someone wants to trade/send me an DAC/AMP combo or something) and would rather not lose it. This brings my options down to installing the 2nd GPU in the PCI-E 4x slot. Since crossfire is limited by the weakest GPU, the 4x slot will bring my 16x slot down to 4x as well. Being newer to multi-card setups I don't know what kind of performance impact this is going to have.

 

I have a PCI slot ribbon extender on the way with my crossfire bridge to hopefully work around this, but since both cards have aftermarket coolers on them I'm worried about clearance with the cooler and the ribbon extender. If it works then all will be well but I wanted to start brainstorming backup plans in case it doesn't go as I intend it to.

 

What do you think would be the best way to work around this slot problem? Is the performance impact of the PCI-E 4x slot minimal enough to just ignore?

dont use the x4 slot for the GPU

 

esp with high end GPUs and CrossFire

 

the performance hit will be huge 

 

find a way to extend the PCI slot for the sound card or forgo the sound card entirely

[-rascal-]

So I have a bit of a predicament....my PCI slots go in the following order:

 

PCI-E 1x

PCI-E 16x (GPU 1)

PCI-E 4x (Covered by GPU1)

PCI-E 16x

Standard PCI (Populated by sound card)

PCI-E 4x

(All 2.0 slots)

 

Ideally as understand it I would want to use the PCI-E 16x slots for the graphics cards. The problem with this is that the PCI slot will be ran over by the second GPU whenever I add it, which means I can't use my sound card anymore. Well I kind of like my sound card (unless someone wants to trade/send me an DAC/AMP combo or something) and would rather not lose it. This brings my options down to installing the 2nd GPU in the PCI-E 4x slot. Since crossfire is limited by the weakest GPU, the 4x slot will bring my 16x slot down to 4x as well. Being newer to multi-card setups I don't know what kind of performance impact this is going to have.

 

I have a PCI slot ribbon extender on the way with my crossfire bridge to hopefully work around this, but since both cards have aftermarket coolers on them I'm worried about clearance with the cooler and the ribbon extender. If it works then all will be well but I wanted to start brainstorming backup plans in case it doesn't go as I intend it to.

 

What do you think would be the best way to work around this slot problem? Is the performance impact of the PCI-E 4x slot minimal enough to just ignore?

 

As @dragoon20005 mentioned, don't use the PCI-E X4 slot if possible.

 

The option I see, if you want to continue to use a Sound Card, is to get a PCI-E X1 sound card, and install it in the top-most PCI-E X1 slot. You could use the PCI-E X4 slot for a sound card instead, but it may obstruct the lower graphics card from airflow.

[guyf2010]

I don't notice issues, with my second card in a 4x slot, if I remember correctly, reducing PCIE bandwidth to 4x only has a 5% performance impact. Also, a number of people say put the 280X in the top slot, I'd say put whichever runs cooler in the top slot, as the air is restricted by the second card. Putting the GPU in the 4x slot also gives some breathing room for the top card. You may want to make sure there are no issues putting a card on the bottom slot. Does the case have an extra PCIE slot below the bottom port for the GPU to screw into? Are any important connectors going to be covered by the cooler? My second card stops me from using the USB 2.0 headers and the HD Audio headers, I managed to squeeze in the front power LED/Switch, but my Reset switch and HDD LED are unplugged.

[TheVoiceofExile]

I don't notice issues, with my second card in a 4x slot, if I remember correctly, reducing PCIE bandwidth to 4x only has a 5% performance impact. Also, a number of people say put the 280X in the top slot, I'd say put whichever runs cooler in the top slot, as the air is restricted by the second card. Putting the GPU in the 4x slot also gives some breathing room for the top card. You may want to make sure there are no issues putting a card on the bottom slot. Does the case have an extra PCIE slot below the bottom port for the GPU to screw into? Are any important connectors going to be covered by the cooler? My second card stops me from using the USB 2.0 headers and the HD Audio headers, I managed to squeeze in the front power LED/Switch, but my Reset switch and HDD LED are unplugged.

No connector conflicts when I did a test fit (soundcard removed). Both cards are the open cooler design so temps shouldn't be too big of a problem. Fortunately my motherboard has a PCI and a PCIE 4x slot as the bottom 2 slots meaning I won't have to worry about bottom clearance for dual or tri-slot cards so long as I have them both in the PCIE 16x slots.