AMD has been quiet for the past few months after the launch of their RX 6700 XT, but they have still been busy in that time. Just last week they announced their RX 6600 XT. The 6700 XT was targeted at 1440p, but the new RX 6600 XT is still focused on high performance 1080p gaming which is still by far the most popular gaming resolution being used. The 6600 XT doesn’t have a reference design, so today I will checking out the MERC308 version from XFX to see how the 6600XT performs in our test suite. Is it going to be the best option for someone looking to get the best performance at 1080p? We will find out.

Product Name: XFX MERC 308 RX 6600 XT Black

Review Sample Provided by: XFX through AMD

Written by: Wes Compton

Amazon Affiliate Link: HERE


RX 6600 XT

Before diving into the details on the XFX specific MERC 308 that we have on hand. I did want to take a look at the base specifications of the RX 6600 XT and go over what sets it apart from the RX 6700 XT that we previously took a look at and last generations RX 5700 XT and 5600 XT as well. For that, I have all four models broken down below. The 6600 XT comes in relatively close to the 5700 XT and 5600 XT for transistor counts, with it having 11.1 Billion compared to 10.3 and this is a lot lower than the 6700 XT. Even though it has the same manufacturing process they managed to fit the higher transistor count into a smaller die size which can help keep costs down. Especially right now when you have such a shortage on the silicon production side of things. The 6600 XT has fewer compute units at 31, but like the 6700 XT, it now adds in the ray accelerators as well which match the compute unit count. The number of stream processors is down from the last generation as well at 2048 but clock speeds are up significantly. The 5600 XT had a boost clock of up to 1560 MHz where the 6600 XT at reference speeds (our XFX card is overclocked) can reach up to 2589 MHz. That clock speed as well as architectural changes with RDNA 2 help it have a peak single precision performance of 10.6 TFLOPS which is up over the 5700 XT even with it having over 500 more stream processors. The 6600 XT has a smaller Infinity Cache of 32MB compared to the 96MB of the 6700 XT and they stuck with the 8GB of GDDR6 that both the 5600 XT and 5700 XT had where the 6700 XT has 12GB. The 6600 XT also has a much smaller memory interface which is 128-bit. Board power is just a touch over the 5600 XT at 160W and 70 watts below the 6700 XT.


RX 5600 XT

RX 5700 XT

RX 6600 XT

RX 6700 XT






Manufacturing Process





Transistor Count

10.3 Billion

10.3 Billion

11.1 Billion

17.2 Billion

Die Size

251 mm²

251 mm²

237 mm²

335 mm²

Compute Units





Ray Accelerators





Stream Processors





Game GPU Clock

Up to 1375 MHz

Up to 1755 MHz

Up to 2359 MHz

Up to 2424 MHz

Boost GPU Clock

Up to 1560 MHz

Up to 1905 MHz

Up to 2589 MHz

Up to 2581 MHz

Peak Single Precision Performance

Up to 7.19 TFLOPS

Up to 9.75 TFLOPS

Up to 10.6 TFLOPS

Up to 13.21 TFLOPS

Peak Half Precision Performance

Up to 14.4 TFLOPS

Up to 19.5 TFLOPS

Up to 21.21 TFLOPS

Up to 26.43 TFLOPS

Peak Texture Fill-Rate

Up to 224.6 GT/s

Up to 304.8 GT/s

Up to 331.4 GT/s

Up to 413 GT/s






Peak Pixel Fill-Rate

Up to 99.8 GP/s

Up to 121.9 GP/s

Up to 165.7 GP/s

Up to 165.2 GP/s

AMD Infinity Cache



32 MB

96 MB






Memory Bandwidth (up to)

288 GB/s

448 GB/s

256 GB/s

384 GB/s

Memory Interface





Board Power






So where does the RX 6600 XT fall in AMD's product stack? Well in their presentation they broke things down nicely by resolution. The RX 6800, RX 6800 XT, and RX 6900 XT are all focused on 4K which is shown by their 16GB memory. The RX 6700 XT is targeted at 1440p with its 12GB of memory, and the RX 6600 XT is focused on 1080p with its 8GB.

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Now they are targeting the 6600 XT at the high end of 1080p with high refresh gaming in mind. It also has all of the same features that the rest of the cards have like smart access memory and FidelityFX super resolution.

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I mentioned it in our opening, but it's not a surprise at all why they would still be focusing on 1080p gaming. Even in 2020 over 2/3 of gaming displays shipped at 1080p. This came as a surprise to me. I know that a majority of monitors out there would be in the 1080p range from sales in the past. But prices on 1440p and even 4k have come down a lot as a whole and especially in the “gaming” displays as they mention here those higher resolution monitors are normally what we see the most. But 1080p is sticking around for a long time to come if a majority of sales last year were still 1080p. The 1080p high refresh range of video cards are also very important because that is where a lot of professional or aspiring to be professional gaming is being down.

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Now before we get into the features of the XFX MERC308 RX 6600 XT Black I did want to mention where that specific model fits into XFX’s 6600 XT product stack. This is especially important with how tough cards have been to get. They have the MERC 3080 Black, the QICK 308 Black, and the SWFT 210 Core. The SWFT 210 is a basic 2 fan model with no overclock running the reference clocks mentioned above. Then the MERC and QUICK are both similar having the same overclock and a similar card design. They have a boost clock of 2607 MHz vs the 2589 MHz of the reference design. The difference between them is in the extra features. The MERC has the silver trim, LEDs, and all of the flair where the QICK has the same cooler and fans with a basic black fan shroud.

Also for reference, I did run GPUz on our MERC 308 to confirm that it did have the specifications listed. This also documents the BIOS revision we tested with and the driver which was the 21.8.1 driver AMD provided for the press for the launch.

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