XFX SPEEDSTER MERC 310 AMD Radeon RX 7900 XT Review

Bigger and faster than the reference 7900 XT, but…

This is it: review day for AIB partner cards! It’s also launch day for AMD’s new Radeon RX 7900 Series cards, which you probably already knew if you got up early and started trying to buy one. Now that partner cards have been added to the mix, selecting your next Radeon just got a lot more complicated. Or maybe it got less complicated.

Let me explain. At $899, AMD’s Radeon RX 7900 XT makes little sense, when for just $100 more you can get the significantly faster Radeon RX 7900 XTX. This is assuming you are going with reference cards and can actually buy one at list price. Clear enough?

Well, once partner cards enter the equation, you will soon see price overlap between AIB RX 7900 XT designs and reference RX 7900 XTX cards. So, unless a factory overclocked RX 7900 XT can out-perform a reference RX 7900 XTX, buying the AIB XT over the XTX makes about as much sense as AMD pricing the two reference cards $100 apart.

Got it? Well, I’m glad you’re excited about XT cards now, because we are going look at an RX 7900 XT partner card that will actually cost $20 less than a reference RX 7900 XTX! Could this be the $979 option that will get you hyped for the XT? Do GPU prices make any sense anymore? Let’s find out!

Be sure to check out our initial review of the Radeon RX 7900 Series cards for more specs and information about these new GPUs.

The XFX Speedster MERC 310 Card

This new MERC 310 design is quite impressive in person, with a level of polish that I haven’t seen from an XFX product up to this point. This isn’t to say that previous cards have been poorly made, but XFX even states that this is the best design they have ever done – and that is going back some 20 or so years (back to their NVIDIA partner days…).

The card looks and feels solid, and there is a fit and finish to it that you just don’t see with computer expansion cards very often. In fact, outside of NVIDIA, this might be the most sophisticated design you’ll see this generation. Just look at that aluminum rear construction! Sure, there are those who find AMD’s latest reference design to be perfect, and others could argue that my subjective rambling about the look and feel of the MERC 310 is irrelevant. Fine.

Moving on to card dimensions, and this isn’t small. In fact, it’s almost RTX 40 Series-sized. The MERC 310 RX 7900 XT measures some 344 mm in length, 128 mm in height, and is 55 mm thick (“2.7 slot”, as XFX puts it). In inches the card is 13.5 x 5.04 x 2.17, but no matter how you measure it this isn’t going to fit in all the same places as the reference RX 7900 XT.

Within all of that volume is a triple-fan cooling system which incorporates straight-through airflow venting which “significantly improves cooling and compliments open design of the Ghost Thermal floating shroud design along with numerous other cooling features”, according to XFX. XFX has also brought back a vapor chamber design for the cooler’s heatsink.

Now, you may be concerned about such a large card, and maybe you didn’t think you would have to deal with a long, heavy card if you stuck with Team Red this generation. Well, fear not, as XFX has included a support system that you can use to prevent card sag – even in cases that don’t offer any GPU support.

Rather than try to photograph it or describe it, how about a video dedicated to this Z Support Bar? (YouTube embed below.)

We can’t forget about performance, and to this end XFX has given the MERC 310 RX 7900 XT Black Edition a healthy factory overclock, with the Game Clock boosted up to 2220 MHz (from the reference 2025 MHz), and the Boost Clock up to 2560 MHz (from 2394 MHz reference). Memory is unchanged from reference, so we are still looking at a card with 800 GB/s of available bandwidth.

Performance Testing

Using the same press driver as our initial RX 7900 XT results, published yesterday, and on the same platform, we begin exploring the performance potential of this XFX card. Please note, however, that overclocking will have to wait for a follow-up post.

We begin with 3DMark results. First, we check out how the overclocked 7900 XT card fares against the reference model in the standard DirectX 12 test Time Spy Extreme, rendered at 3840×2160, and then move on to the DirectX 12 Ultimate test, Speed Way, which is rendered at 2560×1440.

A nice little jump over the reference card in these 3DMark tests, as this architecture does indeed scale with clock speed. Next we’ll look at how the XFX card fares with game benchmarks.

Performance isn’t much better than reference in Cyberpunk 2077 at these settings – but I want to point out that the result here, with major stuttering issues and really bad 1% lows, was limited to Cyberpunk 2077, of which I am running version 1.61. Before you compare these results to other outlets, and accuse me of incompetence or bias, make sure you are comparing results with this version of the game. I have found significant framerate issues with the most recent drivers (as of this weekend) and a reference RX 6800 XT, as well.

There are a lot of variables to consider, and I am probably not testing like many of the other outlets – beginning with the use of 3440×1440 resolution. I am currently running running Windows 11 21H2, and the latest chipset driver from AMD as of the RTX 4090 launch. I am using a Ryzen 9 7950X processor with AGESA 1.0.0.3 microcode on an X670E motherboard, but AGESA 1.0.0.4 is now available, which could potentially have an impact on 1% lows. I am tempted at this point to move over to an Intel platform with the same graphics drivers…

Digression aside, we now look at results from DiRT 5:

We see an increase of 4 FPS in DiRT 5 at 3440×1440 / ultra settings (including raytraced shadows) over the AMD reference card. This is better than the Cyberpunk result, obviously, but we are still looking at an uplift of less than 4% over reference.

Next we will look at Metro Exodus Enhanced Edition, which is admittedly not the best choice for Radeon graphics cards, but I had recently re-tested the game with a handful of GeForce cards and I wanted to see how RDNA 3 could handle the game. (I began testing these cards with the original version of the game, which uses no raytracing even at the “extreme” preset, but I didn’t finish in time.)

While the RX 7900 Series cards don’t fare as well with raytraced titles like this, we are still up at the RTX 3090 Ti level with these new GPUs. The XFX MERC 310 RX 7900 XT manages to produce about 2.5 FPS over the reference, but this is just not enough to close the gap with the XTX.

GPU Clocks, Power Consumption, and Thermals

Just how much higher were the clock speeds from the MERC 310 Black Edition? Just look at this (as reported by GPU-Z):

That is quite the increase. About 150 MHz, pretty much across the board. If we average one of the ten runs – I picked run #10 because at that point the card was running for several minutes and had reached its final load temps – we find some interesting results. The XFX MERC card averaged 2492 MHz, while the reference card averaged 2347 MHz under the same conditions.

Everything has a cost, and those higher core frequencies do indeed involve higher power draw – as you may be able to identify in the messy-looking chart below.

Using a simple line chart type for this becomes hard to read very quickly, but the important thing is at the top of the chart, where the red line (the XFX card under review) is generally drawing 30 to 50 watts above the reference card, peaking at 390 watts. This is approaching what we saw from the reference XTX card, but obviously we aren’t reaching that level of performance.

For those curious, we are using the NVIDIA PCAT hardware for power monitoring, which is a direct inline method that separately logs both PCI Express connector and slot power draw in real time. The “total watts” number here is a combination of both values.

As to thermals, these are excellent, as one would expect considering this cooler is also found on XFX’s XTX version of the card. During our looped Metro Exodus testing we saw load temps of just 57 C core, 73 C hot spot in an ~18 C room. Fans were very quiet under load, spinning up to a max of 1500 RPM. At idle the card is silent (zero RPM).

Final Thoughts

XFX has produced a very nice design for their MERC series once again, with factory-overclocked performance that remains cool and quiet, complemented by an attractive aesthetic. Unfortunately for XFX, at $979 USD the card is only $20 from a reference RX 7900 XTX ($999 USD), though our MERC 310 “Black Edition” card offers higher clocks than the vanilla MERC 310 RX 7900 XT, which should retail just below this at $949 USD.

AMD has positioned these RX 7900 cards as the value alternative to NVIDIA’s RTX 4080, but does partners no favors in pricing the XT and XTX $100 apart. We knew going into this launch that there would be pricing overlap, and here XFX makes the decision to keep this card below the $999 mark, which is admirable considering there ARE $999 7900 XT designs out there.

I’m just stating the obvious here, but if performance was really close between the XT and XTX, similar retail prices would be ok as shoppers could just get what was available. But the XT – even this overclocked version – isn’t close to the XTX. The $899 reference price feels temporary; as if AMD is simply waiting to see where NVIDIA positions their next GPU.

If you like what you see from XFX with this design, I would be suggest looking at their Speedster MERC 310 RX 7900 XTX, instead. AMD’s more powerful GPU is really better suited to a premium product like this. Really, however, I suggest waiting until NVIDIA releases their RTX 4070 or whatever it will be called, as reduced prices / rebate offers are not out of the realm of possibility with these RX 7900 XT cards. Unless there is scarcity, in which case there won’t be any reason to discount anything.