AMD Radeon R9 295X2 CrossFire Video Card Review
Got extra PCIe slots and have no idea what in the world you can do with those? Well if you have $3000 burning a hole in your pocket, wiring in your house that is up to code, a good air conditioning system, and a Type C fire extinguisher that you are not using, AMD's Radeon R9 295X2 QuadFire may be just what the fire marshal ordered.
If you have been living under a rock for the last few weeks then you missed the announcement of the fastest video card on the planet. On April 8th, 2014 AMD announced the AMD Radeon R9 295X2 video card. This single video card contains two full specification AMD Radeon R9 290X GPUs to enable CrossFire on a single card. This means dual-R9 290X performance out of a single card taking up only two slots. AMD set the MSRP on this performance beast at $1,499. The XFX variant is selling for $1529.99 with Prime Shipping.
The make this monster work AMD employs a custom Asetek closed loop liquid cooling system along with some air cooling to keep both GPUs cool and the power supply components cool. There are two pumps, one atop each GPU which exchanges heat out to a separate 120mm radiator with fan. This cooling system proved to be more than adequate at keeping both GPUs cool for hours of gaming. The cooling is so good that AMD even slightly bumped up the clock speed to 1018MHz on each GPU for a little performance boost over a regular AMD Radeon R9 290X GPU. What's more, the clock speed was consistent, never failing, and never throttling performance.
In our evaluation we experienced gameplay that was absolutely phenomenal. We tested in an Eyefinity configuration on three displays at 5760x1200 and pushed the limits on a 4K display at 3840x2160. The AMD Radeon R9 295X2 never missed a beat, delivering rock solid performance and gameplay.
What then could be better than one AMD Radeon R9 295X2 video card? How about two in CrossFire for"QuadFire" performance! That's what we have to show you today.
How To: AMD Radeon R9 295X2 x2
Though the announcement of the AMD Radeon R9 295X2 was on April 8th, 2014, AMD made it clear retail availability would not arrive until the week of April 21st. April 21st also marked the official date that the embargo lifted on the publishing of "QuadFire" or two Radeon R9 295X2 video cards with CrossFire enabled delivering four GPUs worth of performance.
We of course only had one R9 295X2, and AMD at the time had not sampled anymore out so we were out of luck until we reached out to Ryan Shrout at PCPerspective.com. We agreed to borrow each other's R9 295X2 video cards with a same-day publishing date in mind. We quickly took shipment of Ryan's AMD Radeon R9 295X2 and here you have our evaluation today.
Before we dive into setting up two AMD Radeon R9 295X2 video cards we need to re-post the documents explaining how to properly connect power to these. There are strict power requirements, and with two of these video cards it is even more important. We encountered an issue, not related to amperage, but related to wattage we will discuss below.
In the above pictures you can see our two AMD Radeon R9 295X2 video cards side-by-side. This is what $3,000 buys you from AMD in terms of gaming performance.
Dual AMD Radeon R9 295X2 CrossFire (QuadFire)
Before we explain the issue we had, and the fix we had to make to get things working let's show you what this would look like if you have the proper PSU.
With two AMD Radeon R9 295X2 video cards you will need to find a place to mount both radiators in your system. The tubes are long enough that you could place one radiator above the video card on the exhaust fan position of your case. The second radiator can go in a fan position on the front of your case. We suggest you set these fans up exhausting the case.
In idle the second video card will shut down, however the radiator fan will remain spinning to maintain airflow in your case. This is a nice feature AMD enabled so the airflow stays moving.
Remember, no cables or connectors are needed between the two video cards. These cards support the new CrossFire technology that allows everything to take place between the PCI-Express bus. Also note that on our motherboard it allows room between the video cards so these can breathe. This is important on these video cards because the memory, and power circuitry is all actively cooled by a center mounted fan.
If you have a proper PSU for this to work make sure you follow the diagram above in the PDF. You cannot use both power connectors on a cable that splits off into two, or shares the 12V rail with any other component. You need dedicated 8-pin connectors to each video card. You also need to make sure at least 28 amps are supported on each 12V rail. If these factors are not maintained, wire overheating and melting situations could occur. Beyond that, you will also need the proper wattage to support two of these video cards, and it is a lot. 1500W is suggested at the least.
The PSU Wattage Problem
In our evaluation system we are using an Enermax MaxRevo 1350W PSU. This is a beefy power supply that has served us well in testing and has allowed us to use any combination of video cards, up to 4 GPUs on previous generations without issue. In fact, the max support amperage is 30 amps per 12V rail, so the ratings in terms of amps are than what AMD recommends. We had no issues with this power supply and one AMD Radeon R9 295X2 video card. However, we did have problems with two.
The problem was a simple one to diagnose, we ran out of wattage. Our 1350W was not enough to run two AMD Radeon R9 295X2 video cards in CrossFire on our overclocked system. Note that our system runs lean, we do not have an optical drive, we have only one SSD, everything on the motherboard is turned off except what we need. The two major power drains are our CPU which is an overclocked Intel Core i7 3770K at 4.8GHz and the GPUs.
The issue we ran into was that the games would start just fine, but as we got going the wattage increased on our power meter (at the wall) until it rose above 1350W and the PSU would then shutdown. We needed more wattage to make gaming work, simply put. Since we were under a very strict time scale to complete our testing, and because we did not have a spare 1500W PSU on hand nearby we made this work in another way.
We borrowed another PC’s PSU to power one of the video cards by itself, taking the load off of our main PSU. We plugged two dedicated 8-pin power connectors from the 850W PSU to the second AMD Radeon R9 295X2 video card. We disconnected everything else in the computer and used the ole pin trick to jump start the PSU so it would provide full power to the video card. This worked flawlessly.
With the combined wattage measured at the wall with our power meter we were pulling 1400W with dual AMD Radeon R9 295X2 CrossFire and the rest of the system.
Comparison Cards? Not So Much.
We wanted to bring you a full and worthy comparison to the competition today, that being the latest and greatest NVIDIA has to offer. There is the Titan Black, and the new Titan-Z that we were anxious to give a go to bring you performance from the competition that would best match AMD Radeon R9 295X2 CrossFire. We reached out to NVIDIA's Senior PR Manager of Consumer Products Bryan Del Rizzo and asked:
We are planning a R9 295X2 QuadFire review. Would NVIDIA like to have a contender in this review? If so, let me know what you might have.
The reply we got back from Bryan Del Rizzo was:
In response we will just be showing you how QuadFire compares to one AMD R9 295X2 as well as a single GPU AMD Radeon R9 290X. We are using an XFX R9 290X DD as our single-GPU card at 4K and Eyefinity because it does not throttle performance. We are using a stock AMD Radeon R9 295X2 and then two stock AMD R9 295X2 cards in CrossFire. In this way we can see how performance scales up from one GPU, to two GPUs to four GPUs.