Conclusion

There's something to be had for everyone who successfully flashes their Radeon RX 5700 with the BIOS of the RX 5700 XT. For those who just want to flash their card and leave it, there is a free 7 percent performance boost to be had that's permanent and doesn't require playing with any tweaking dials. If you're feeling just a little bit adventurous, you can max out the power limit, which results in an additional 2%, giving you 8-9 percent performance over the stock RX 5700. The beauty of this approach is that your card will be 100% stable at all times, and you don't have to deal with AMD's finicky overclocking controls, which results in system hang after system hang until you've found the right settings. This config is what we recommend for the majority of gamers who don't feel like they're overclocking experts.

If you do want to gain more and are willing to play a bit with the settings, the next level is some manual overclocking, which should yield you another percent—not sure if it's really worth the trouble. What could be beneficial though should be some mild undervolting (just set manual OC and drag down the top voltage point a bit). This reduces power consumption and heat output, which brings down temperatures.

Overall, there's excellent potential in the Radeon RX 5700, letting you squeeze up to 9% of performance out of your RX 5700 with no overclocking, and up to 10% with some on-air overclocking. Something like this on the stock RX 5700 BIOS would simply not be possible because AMD's Wattman limits wouldn't allow it. The only approach is soft-PowerPlay tables, which basically put an alternative limits table into your Windows registry, overriding the one in the BIOS. A software for this is MorePowerTool. What makes things complicated (beyond the large number of options available), is that you have to reinstall the custom PowerPlay table on every driver update, and AMD could remove this ability from future drivers with ease.

Where's the secret sauce in all this? AMD has engineered the Radeon RX 5700 as a power-efficiency marvel to go head-to-head with NVIDIA's Turing architecture. The catch is that the card runs extremely low voltages at all times, which of course limits achievable maximum clock rates. On top of that, the power limit is set fairly low, which further caps the card's capabilities. The RX 5700 XT, on the other hand, has much higher limits. Flashing the RX 5700 XT BIOS gives the RX 5700 its increased limits, much higher boost headroom, and much better boost state sustainability. You increase these even further by manually bringing up the power limit. With these tiers of tweaks, the RX 5700 ends up barely 4 percent behind the RX 5700 XT, which at this point only has 256 additional stream processors and 16 TMUs making the difference.

Since we're comparing two nearly identical cards based on the same silicon, there are no games in particular where the variance between a flashed RX 5700 and RX 5700 XT is high. The RX 5700, at least the AMD reference design card, is at a slight disadvantage compared to the reference RX 5700 XT when it comes to cooling. The RX 5700 XT has slightly better airflow due to its contoured air channel, and probably more meat on the heatsink to vent out the heat. Fan noise of the RX 5700 remained unchanged throughout all our testing because AMD has configured both the XT and non-XT to never run above 2100 RPM fan speed no matter the temperature. Since heat output obviously goes up with the new BIOS, this is purely reflected in temperatures that do end up higher, but aren't critical in any way. The RX 5700 XT reference actually runs warmer than our flashed card, and you'll always have thermal throttle protecting the card from any damage.

So, should you do it? If you feel confident and have the right BIOS ROM image file with you, go for it. It's an almost 7-10 performance boost without the pains of manual overclocking. The RX 5700 XT will end up being just 4 percent faster while being almost 15 percent pricier.