My adventure with a used 5700 XT.
I recently bought a used reference Radeon RX 5700 XT blower card, I thought it was a pretty good deal for $300 shipped to me. I was a little worried because the guy claimed to have already done the washer mod on it. But I went ahead and bought it anyway. I stuffed it in and began testing. Temps were scorching. 90*C CPU, and 110*C Junction temps. Memory was in the low to mid 90's. VRM temps were around the high 70's to mid 80's. It was a disaster. (Edit: I failed to mention originally this was all done with an extremely aggressive fan curve that sounded like a vacuum cleaner during gaming), It wouldn't hit over 1815 for clock speeds but averaged around 1750. Thermal throttled hard. I decided to pull it apart and see what I could do. In the process I accidentally broke the connector off the board that goes to the lighting for the Radeon logo on the fan shroud, and I also broke two wires off the fan connector right where they plug into the connector
. Not because I forgot to disconnect them, but because of how difficult it is to get to them in order to disconnect them, and trying to use regular pliers wasn't a good idea. Had I taken the time to fetch some tweezers I could have saved a lot of time. Luckily I'm an electronics tech and a little soldering later, I had the plug back on the board and found an old fan connector on an older graphics card to splice the wires together for a new fan connector. After all that I get it apart and it turns out the individual I purchased it from had indeed done the washer mod. He just forgot to remove the stock graphite thermal pad between the die and heat sink before applying thermal paste and putting it back together (see pic below).
So I removed it. Slapped the card back together cleaning up his thermal paste and graphite pad, and adding some arctic silver 5. That dropped everything about 7*C which was still too hot for my tastes.
So I decided to fix it. I knew that lapping the heat sink could prove beneficial, especially after seeing how concave the markings on the graphite pad were and the pattern of the thermal paste (see the pic below after removing the graphite pad). It had a very significant bowl shape in the middle of the die contact plate. I guess there is no such thing as engineering quality control at the Radeon factory because I never would have sent that heatsink out the door on a card like that. So I got my drill, some sand paper and spent an afternoon removing some copper. I knew Conductonaut (thermal grizzly's liquid metal) tends to drop temps nicely. I also knew that Fujipoly 17 W/mk thermal pads do a nice job dropping temps also. I used both on an old laptop to do some overclocking and get a year more of use out of it a while ago, and I had still had the liquid metal and Fujipoly pads laying around. I used 1.0 mm thick pads for the memory chips and .5mm for the VRMs and other components on the board that I could see made contact with the plate. So between the washer mod, flattening out the contact plate a bit (it's still slightly concave but I didn't want to remove too much copper), liquid metal, and new Fujipoly thermal pads things worked out nicely.
New temps are beyond my expectations after 20 minutes under full load running Fire Strike Extreme Stress Test with no detectable artifacting.
CPU temp averages 64*C, the max I saw it was 73*C
Junction temps will not go above 80*C
Memory maxes out at 80*C
Highest VRM temp is 64*C
average clock speed is 1995 with boosts to 2005
Undervolted to 1100 (anything below that gets unstable or artifacts start showing up), with frequency set to 2044 and Power cranked to max. Under full load it draws up to 217 Watts, but sits around 190 to 200.
Fan curve is a little aggressive and I could turn it down if I wanted to drop the clocks and power a bit, but I use headphones anyway and can't really hear it with them on. I haven't touched the memory frequency yet and probably won't unless I drop the clocks down to make the fans quieter.
Overall I was pleasantly surprised with the drop in temps. It was a really hot card and I brought it into the realm of what some of the better partner boards are doing out of the box. So for $300 and a little work I'm pretty happy with it. So If you have a hot card like mine you might want to try the liquid metal and Fujipoly pads, or try an aftermarket cooler. Also look at the contact plate. If you can see the reflection of a light in it distort really badly as you move it, it probably could use a good lapping.