CF or new graphics card?

[nicholasmita]

Hey there,

I have a single R9 280x in my system right now. Im thinking of giving my pc an upgrade. Either getting a second hand R9 280x and put them in crossfire or getting a new graphics card. Im not sure bout the performance of R9 280x in crossfire and i have 750 watts power supply. The new release of the RX 480 intrigues me. Pretty excited for RX 480x or 490. Whats your thoughts?

Thanks!

Specs:
i7 4790
R9 280x
H97 Gaming-3
16Gb HyperX Savage

 

[Hlsgsz]

Hey there,

I have a single R9 280x in my system right now. Im thinking of giving my pc an upgrade. Either getting a second hand R9 280x and put them in crossfire or getting a new graphics card. Im not sure bout the performance of R9 280x in crossfire and i have 750 watts power supply. The new release of the RX 480 intrigues me. Pretty excited for RX 480x or 490. Whats your thoughts?

Thanks!

Specs:
i7 4790
R9 280x
H97 Gaming-3
16Gb HyperX Savage

A single faster card is always the best solution. That goes double these days as the industry in transitioning from 28nm to 14/16nm witch means higher clocks and performance and 2x power efficiency. Not to mention that 3GB of Vram will become a problem soon.

 

[rhysiam]

With that H97 board you can't split your x16 PCIe lanes, which means your second slot is limited x4 PCIe 2.0 lanes, or roughly 1/8th the bandwidth of your x16 PCIe 3.0 slot. It's not a great idea to CFX in that situation.

Wait for benchmarks, but the 480 is looking like it would give you a pretty significant performance increase over a 280X. Might well be worth upgrading.

 

[Hlsgsz]

With that H97 board you can't split your x16 PCIe lanes, which means your second slot is limited x4 PCIe 2.0 lanes, or roughly 1/8th the bandwidth of your x16 PCIe 3.0 slot. It's not a great idea to CFX in that situation.

Wait for benchmarks, but the 480 is looking like it would give you a pretty significant performance increase over a 280X. Might well be worth upgrading.

Crossfire works very well on H97. It's just not worth it in OPs case, especially with the 480 coming out.
Btw, OP, if you end up getting a 480, get the 8gb version since you seem to be the kind of gamer that is price conscious and whant the best longevity from their cash,

 

[Rogue Leader]

From someone who has 2 R9 280's in CF, don't. Its not worth it. While it benchmarks fast as heck, half the games it doesn't work right, or I get micro stutter, or any other of a number of BS things happen.

Just get a better single card, the RX 480 sounds like its gonna be a great deal.

 

[rhysiam]

Crossfire works very well on H97.

You got benchmarks to support that? I know it technically works, but that's not a lot of PCIe bandwidth on that second slot. I'll admit it's been a good few years since I looked into this, and back then benchmarks were hard to come by, but the general consensus seemed to be that it was probably okay for most games, but it was likely to be an issue from time to time. That was years ago when 7970 (280X) was a premium card that no one would put on a x4 PCIe 2 slot... I don't think it's a good idea on that basis, but I'd welcome benchmarks if you think differently?

In any case, we both agree that the single card solution is the better option.

 

[Hlsgsz]

Crossfire works very well on H97.

You got benchmarks to support that? I know it technically works, but that's not a lot of PCIe bandwidth on that second slot. I'll admit it's been a good few years since I looked into this, and back then benchmarks were hard to come by, but the general consensus seemed to be that it was probably okay for most games, but it was likely to be an issue from time to time. That was years ago when 7970 (280X) was a premium card that no one would put on a x4 PCIe 2 slot... I don't think it's a good idea on that basis, but I'd welcome benchmarks if you think differently?

In any case, we both agree that the single card solution is the better option.

That was correct for PCIE 2. With PCIE 3 it's not teh case anymore

 

[rhysiam]

That was correct for PCIE 2. With PCIE 3 it's not teh case anymore

Look at the H97 specs carefully. One of the fundamental limitations of the H97 chipset is that it cannot split the CPU lanes. So you get one slot which is x16 PCIe 3.0, but these lanes cannot be split onto the second slot. That means your second PCIe slot has to be serviced by the chipset, not the CPU, which limits it to x4 lanes at PCIe 2.0. Haswell CPU is PCIe 3.0, but the chipset lanes are still 2.0. It wasn't until Skylake that we got extra lanes on the chipset and had those lanes bumped to PCIe 3.0 speeds.

A second card on a H97 board will run at x4 PCIe 2.0.

 

[Rogue Leader]

I have to agree, while there are 2 motherboards out there called "Gaming 3" Gigabyte and MSI, they agree on one thing:

http://www.gigabyte.com/products/product-page.aspx?pid=4997#sp

https://www.msi.com/Motherboard/H97-GAMING-3.html#hero-specification

Slot 2 is an "x16" slot... that runs at x4. Not only that it even kills the PCIe x1 slots if you use that slot.

 

[Hlsgsz]

That was correct for PCIE 2. With PCIE 3 it's not teh case anymore

Look at the H97 specs carefully. One of the fundamental limitations of the H97 chipset is that it cannot split the CPU lanes. So you get one slot which is x16 PCIe 3.0, but these lanes cannot be split onto the second slot. That means your second PCIe slot has to be serviced by the chipset, not the CPU, which limits it to x4 lanes at PCIe 2.0. Haswell CPU is PCIe 3.0, but the chipset lanes are still 2.0. It wasn't until Skylake that we got extra lanes on the chipset and had those lanes bumped to PCIe 3.0 speeds.

A second card on a H97 board will run at x4 PCIe 2.0.

You're right. And that would probably affect performance, although CF is supposed to be supported on paper. My bad!