Mobo and PSU(Modular) for Crossfire of 7950's

EoinHef

I currently have a ASRock Pro 4 in my build and ive decided i want the option of Crossfire down the line.
So im looking for a board to support crossfire that i can replace the pro 4 with and a new psu(i want a modular one). I plan to reuse my current psu and maybe the board in another build or sell them on.

I have an i5 3570k aswell that im happy with so id be looking for a 1155 socket motherboard.
Would the i5 bottleneck a pair of 7950's?
Currently running at 4.2GHz

I currently have a sapphire vapor x 7950 so ideally i would just like to get another one of them down the line,its a rather big card though so not sure what spacing i would need on the pci slots.

I know the ASRock Extreme 3/4 motherboards support crossfire so wondering would either of them do with the card spacing in mind,ideally id like a bit of a gap between the two cards for cooling?

Thanks for any help in advance:)

NTMK

EoinHef wrote: »

I currently have a ASRock Pro 4 in my build and ive decided i want the option of Crossfire down the line.
So im looking for a board to support crossfire that i can replace the pro 4 with and a new psu(i want a modular one). I plan to reuse my current psu and maybe the board in another build or sell them on.

I have an i5 3570k aswell that im happy with so id be looking for a 1155 socket motherboard.
Would the i5 bottleneck a pair of 7950's?
Currently running at 4.2GHz

I currently have a sapphire vapor x 7950 so ideally i would just like to get another one of them down the line,its a rather big card though so not sure what spacing i would need on the pci slots.

I know the ASRock Extreme 3/4 motherboards support crossfire so wondering would either of them do with the card spacing in mind,ideally id like a bit of a gap between the two cards for cooling?

Thanks for any help in advance:)

i5 wont bottleneck 7950's @4.2
Extreme 4/6 are spaced to leave a gap
the extreme boards are good boards in my experience
Whats your budget for PSU?:)

U_Fig

according to the Asrock website the z77 pro 4 supports crossfire.. i don't see a massive problem here at all..

for the PSU the be quiet do a semi modualr one that's quite affordable..

BloodBath

The pro's will have one lane running in pcie3 x4 mode in crossfire which will impact performance.

EoinHef

NTMK wrote: »

i5 wont bottleneck 7950's @4.2
Extreme 4/6 are spaced to leave a gap
the extreme boards are good boards in my experience
Whats your budget for PSU?:)

Was hoping to spend around €200,give or take 20 or 30 though if something was still value for money at a little more.

Im quite happy with the pro 4 aswell just pity it doesnt suppot crossfire,well 8x anyway.
Ah i see,wasn sure how you can tell spacing,i couldnt see it on motherboard specs anywhere,is it called something else?

Does that trend continue as you go up the Extreme range of boards? As in the 6 has more space than the 4?

EoinHef

U_Fig wrote: »

according to the Asrock website the z77 pro 4 supports crossfire.. i don't see a massive problem here at all..

for the PSU the be quiet do a semi modualr one that's quite affordable..

It does alright but it only supports 4x which i have been told would not fully utilise the gpu.

Cool,ill have a look at the be quiet range and see what i can see.
Was hoping something in maybe the 700W range would suffice for crossfire,thats probably even too much from what im reading so maybe even something with less power but more efficent?

EoinHef

Oh and sorry i never stated the budget in the OP:(

Hoping roughly 200 would do give or take 20 or 30 though if something is still value for money at a higher price

NTMK

EoinHef wrote: »

Was hoping to spend around €200,give or take 20 or 30 though if something was still value for money at a little more.

Im quite happy with the pro 4 aswell just pity it doesnt suppot crossfire,well 8x anyway.
Ah i see,wasn sure how you can tell spacing,i couldnt see it on motherboard specs anywhere,is it called something else?

Does that trend continue as you go up the Extreme range of boards? As in the 6 has more space than the 4?

I know from working with extreme boards

but if you look at the spacing you can usually tell which boards are spaced properly

you can see on the board that you have:

Pci-e -> space -> pci -> pci-e

that single slot is enough for the GPU to breathe and usually stays the same as you go up the range of extreme boards

EoinHef

NTMK wrote: »

I know from working with extreme boards

but if you look at the spacing you can usually tell which boards are spaced properly

you can see on the board that you have:

Pci-e -> space -> pci -> pci-e

that single slot is enough for the GPU to breathe and usually stays the same as you go up the range of extreme boards

Cool,i see what you mean.
Ive heard the Vapor-X be described as "a 2 and a half slot card" so i suppose i just have to see how much the second pci-e is covered on my current board as the spacing should be the same on the extreme 4?

NTMK

EoinHef wrote: »

Cool,i see what you mean.
Ive heard the Vapor-X be described as "a 2 and a half slot card" so i suppose i just have to see how much the second pci-e is covered on my current board as the spacing should be the same on the extreme 4?

spacing will be the same. i cant really comment on the vapour x cards as ive no experience with them but you should be ok

marco_polo

The thing is PCIe 3.0 x4 is the pretty much the same as PCIe 2.0 x8 so it shouldn't affect performance of two HD 7950s that much. I'd say its probably a gpu generation or two away from really mattering in that price range.

http://www.behardware.com/art/imprimer/850/

Tldr probably not worth the expense of upgrading , purely for performance reasons, unless the slots are too close for your liking on the pro4 and you want to futureproof

EoinHef

marco_polo wrote: »

The thing is PCIe 3.0 x4 is the pretty much the same as PCIe 2.0 x8 so it shouldn't affect performance of two HD 7950s that much. I'd say its probably a gpu generation or two away from really mattering in that price range.

http://www.behardware.com/art/imprimer/850/

Tldr probably not worth the expense of upgrading , purely for performance reasons, unless the slots are too close for your liking on the pro4 and you want to futureproof

Hmmm,i was under the impression that you needed to have both slots running at least 8x on PCIe 3.0 to fully exploit the gpus.And the first slot reverted to 8x when you added a second gpu?
I see what you mean about the PCIe 2 and 3,as in PCIe 2.0 at 8x is equivalent to PCIe 3.0 at 4x. I wonder what the performance hit would be? Find it quite hard to understand the graphs in the link at a glance:P


One of the reasons i was looking at doing this is that i may be looking to make another build and was thinking could just reuse parts i upgrade as in motherboard and psu if i decide to do this upgrade for the second build,im still a little undecided!!

TerrorFirmer

I think marco polos on the ball there - I really think the bandwidth issue is over exaggerated a lot. I've run Crossfire on 16+4x 2.0 and the scaling was good - I'd say with 3.0 4x you'd be talking 5-10% difference tops at a guess.

EoinHef

I thought that PCIe 2.0 at 16x was still ok for modern gpus and that PCIe 3.0 at 16x still was not being totally utilised by most cards but didnt realise the performance loss could be as little as 5-10% with PCIe 3.0 at 4x(PCIe 2.0 at 8x).

What about the power for the board though,would a board like the pro 4 be able to stand up to 2x7950's? With potentially overclocks on both cards aswell,and i have an i5 at 4.2GHz so was thinking maybe the board wasn really designed for that kind of setup?

marco_polo

EoinHef wrote: »

Hmmm,i was under the impression that you needed to have both slots running at least 8x on PCIe 3.0 to fully exploit the gpus.And the first slot reverted to 8x when you added a second gpu?
I see what you mean about the PCIe 2 and 3,as in PCIe 2.0 at 8x is equivalent to PCIe 3.0 at 4x. I wonder what the performance hit would be? Find it quite hard to understand the graphs in the link at a glance:P


One of the reasons i was looking at doing this is that i may be looking to make another build and was thinking could just reuse parts i upgrade as in motherboard and psu if i decide to do this upgrade for the second build,im still a little undecided!!

The gaming graphs at the end are the only one that really matters .

Its not that the primary slot reverts to a lower speed, but rather the close co-ordination that crossfire demands between cards, means the card in the faster slot will effectively be limited by the card in the slower one.

More bandwidth is of course always better, but like faster ram, don't offer nearly as much gains in many applications (Unless you are really near the lower end of the scale).

Bandwidth only affects how fast the CPU and GPU can communicate with each other, but most of the time in a very demanding game, the GPUs will be flat out doing calculations on data it already has in its buffers, and isn;t in a position to accept any more data until it is finished processing the current frame.

Like I said if you have other reasons like a second build then fire ahead with one of the extremes, but its probably not worth it just if you are looking solely for crossfire gains.

EoinHef

marco_polo wrote: »

The gaming graphs at the end are the only one that really matters .

Its not that the primary slot reverts to a lower speed, but rather the close co-ordination that crossfire demands between cards, means the card in the faster slot will effectively be limited by the card in the slower one.

More bandwidth is of course always better, but like faster ram, don't offer nearly as much gains in many applications (Unless you are really near the lower end of the scale).

Bandwidth only affects how fast the CPU and GPU can communicate with each other, but most of the time in a very demanding game, the GPUs will be flat out doing calculations on data it already has in its buffers, and isn;t in a position to accept any more data until it is finished processing the current frame.

Like I said if you have other reasons like a second build then fire ahead with one of the extremes, but its probably not worth it just if you are looking solely for crossfire gains.

Apologies,should have read to bottom of link but it was late and i was very tired! I see it only limits it a tiny amount,also did a bit of digging myself this morning and most places its mentioned theres figures of anywhere between 5-15% hit on performance (by the behardware link though it seems even less) so in light of the cost of the upgrades im looking at,point is taken.

Really didnt realise its not as important to have at least a second 8x slot.

That being said,im still on the fence. Im still thinking about a second build so the board would not be wasted as in sold for little or nothing on adverts.
The pro 4 being a 1155 socket is going to limit my choice of cpu for the second build though,i was looking at putting it into something midrange,maybe pairing it with something like a 7850.
What cpu's would be a good choice for that on 1155 socket? Is the 3570k the only i5 worth getting that overclocks or are there other options for the socket?

As regard the PSU if i was going to upgrade i was thinking either of these:

http://www.hardwareversand.de/500+-+600+Watts/33060/Super-Flower+SF600P14XE+Golden+Green+80plus+gold+Modular.article

http://www.hardwareversand.de/600+-+700+Watts/33057/Super-Flower+SF700P14XE+Golden+Green+80plus+gold+Modular.article

Not sure if the 600W would be enough? They seem cheap for though for high wattage and modular and also gold rated 80+

And for the board i was thinking maybe either of these:

Msi Z77A-GD55: €115.93
http://www.hardwareversand.de/articledetail.jsp?adp=0&aid=57132&agid=1601&apop=1

ASRock Extreme 4: €123.89
http://www.hardwareversand.de/DDR3/57624/ASRock+Z77+Extreme4%2C+Sockel+1155%2C+ATX.article

ASRock Extreme 3: €110.24
http://www.hardwareversand.de/articledetail.jsp?adp=0&aid=67918&agid=1601&apop=606

Asus P8Z77-V LK: €124.28
http://www.hardwareversand.de/DDR3/60079/ASUS+P8Z77-V+LK%2C+Sockel+1155%2C+ATX%2C+DDR3.article

I put the Asus one up because it comes with a three year warranty,although its the same price as the Extreme 4.
Also all them look the same for spacing.

And cheers for the help so far:)

EoinHef

Any opinions on the motherboards and psu's in the above post?
Im leaning towards the extreme 4 and and the 600w if it has enough power
A work colleague is looking to build a pc and hes most likely going to take my old board and psu

BloodBath

I'd probably go with the Asrock extreme3.

Psu's are most efficient in the 40-70% power consumption ranges. I would say overclocked you would be using around 450-500w of power under load so I'd go with more than 600w. 700w should have you covered.

The description on the 700w says it only has 1 x 8 pin and 1 x 6 pin gpu power which I assume is wrong as it says it's sli and crossfire ready. Just make sure whatever you pick has the connections. You could always use adaptors but you might as well get a psu with them on it.

EoinHef

Do you know if the spacing between slots is bigger on the extreme 4 over the extreme 3?

The vapor x has dual 8 pin connecters aswell which im a little worried about alright when it comes to the psu, id need a psu with 4 of those then? Ideally I wouldnt want to use adapters alright. The vapor x does come with 2 of them but they look ****e!

NTMK

EoinHef wrote: »

Do you know if the spacing between slots is bigger on the extreme 4 over the extreme 3?

its the same

BloodBath

Maybe go for this psu?

http://www.hardwareversand.de/700+-+800+Watts/63629/Corsair+Professional+Series+HX750+80PLUS+Gold+750W.article

EoinHef

Thanks NTMK, I reckon the extreme 3 be fine for me then.

Looking at them on amazon there is different versions, gen 2 or gen 3 say. What would be the difference there?

Cheers bloodbath, that psu is only about €10 difference and comes with a 7 year warranty!! Ill be grabbin that, cheers man

EoinHef

Sorry i think the Gen thing is only related to an older chipset (Z68).

I reckon im gonna buy from amazon just for easier returns just incase.
Its very strange but the Extreme 4 seems to be 1 pound cheaper than the extreme 3??

Extreme 3: GBP 102.45
http://www.amazon.co.uk/ASRock-Z77-EXTREME3-Extreme3-Motherboard/dp/B0096WJ27K/ref=sr_1_2?ie=UTF8&qid=1374517958&sr=8-2&keywords=asrock+extreme+3+z77

Extreme 4: GBP 101.61
http://www.amazon.co.uk/Z77-Extreme4-Motherboard-Supports-CrossFireX/dp/B007KTY4A6/ref=sr_1_1?ie=UTF8&qid=1374517958&sr=8-1&keywords=asrock+extreme+3+z77

Am i missing something?

marco_polo

Not missing anything Amazons component prices tend to be all over the place, never much consistancy.

EoinHef

Guess i should probably order it now in case it changes.

Its €2 cheaper ordering from amazon over HWVS this time for the extreme 4 and psu,and only an extra €8 over the price of the extreme 3 and psu from HWVS.
So i reckon ill go with amazon for the sake of €8 and getting a better board,i might as well.

Does anybody reckon they might discount the z77 boards anytime soon with haswell launched now?

EoinHef

Ordered the Extreme 4 and bloodbaths suggested psu off amazon.
Went with the Extreme 4 because it was only GBP1 more than the Extreme 3 so though why the hell not!


Thanks for the advice and suggestions lads,and NTMK for the spacing info.

Hopefully ill be able to get a second gpu and a 1440p monitor by next year

EoinHef

Just lookin at the 670's in the bargain thread from OCUK and was wondering if 2 of them in sli would be comparable to 2 7950's (sapphire vapor x) in crossfire?

I had planned to run dual gpus next year and get a 1440p monitor so would the extra vram on the AMD cards be worth it? Could get 2 670's delivered for circa €450 and at the moment a second 7950 would be over €300 including delivery. So was thinking sell the 7950 and buy the 2 670's or should I hold out for a price drop on the 7950?

BloodBath

You can get good 7950's for about €255. By next year I would say even less. If you bought second hand I'd say less than €200.

http://www.amazon.co.uk/Gigabyte-7950-Radeon-Graphics-Card/dp/B0071LP5ME/ref=sr_1_1?ie=UTF8&qid=1376252793&sr=8-1&keywords=7950

http://www.amazon.co.uk/Sapphire-11196-09-40G-HD7950-Vapox-X-Graphics/dp/B0091MFBZC/ref=sr_1_2?ie=UTF8&qid=1376252793&sr=8-2&keywords=7950

EoinHef

The cheapest vapor x I found was on pixmania for €289 not including delivery. They must have dropped a bit on amazon over the last few weeks, last time I checkeed the lowest price from all sellers was £255 I think.

Thanks for the heads up, ill hang on so.

EoinHef

Cool thanks, cheapest vapor x I could find was on pixmania for €289 not including delivery. They must have had a price drop on amazon cause when I checked a few weeks ago im sure the cheapest from any seller was £255.

Ill hang on so, cheers.