Popular hardware monitoring tool HWInfo64 has just received a new update, version 6.42 that adds support for “GDDR6X Memory Junction Temperature.” This feature will allow you to check your VRAM temperature if you have a GDDR6X equipped Ampere card like the RTX 3080 or RTX 3090. This could be particularly useful if you own a Founders Edition model, as several months ago we reported on a discovery from Igor’s lab in which GDDR6X modules on the RTX 3080 Founders Edition model ran dangerously hot.

After some testing with the new HWInfo64 version 6.42, we’ve validated these same high VRAM temperatures that Igor discovered. Looping Metro Exodus at 4K Ultra settings for several minutes on an RTX 3080 Founders Edition allowed the GDDR6X modules to hit a peak temperature of 102C. The TJmax for GDDR6X is 95C.

However, this changes when enabling DLSS and Ray Tracing. The RTX 3080 with Metro Exodus at the same settings hit a peak temperature of 94C. We also tested an RTX 3090 Founders Edition in Cyberpunk 2077 with DLSS and Ray Tracing enabled. GDDR6X temperatures for that card peaked at 100C.

But when it comes to Ethereum mining, temperatures go to a whole other level: When mining on both the RTX 3080 and RTX 3090, we found that the GDDR6X modules would peak at a much higher 110C, and the GPU would downclock itself severely to compensate for the ridiculously high VRAM temperature. This occurred on multiple different boards, from various vendors. And that’s before applying any overclocking settings, which some miners like to do in order to chase every last bit of hashing performance.

There are ways to reduce the GDDR6X temperatures, which appear to cause the 3080 and 3090 to throttle only once the temperature reaches 110C. We used MSI Afterburner to drop the GPU and GDDR6X clocks as far as possible (-450 MHz on the core and -502 MHz on the RAM), which didn’t really do much. After a few minutes, the cards would still drop down to much lower GPU clocks (around 900-950 MHz), though mining performance was still decent (95MH/s). Decreasing the power limit to just 60 percent finally allowed the VRAM temperatures to drop down to 90C, but then mining performance also dropped to around 60-65MH/s.

These high junction temperatures do give us some cause for concern, but it’s not clear how they’ll affect the cards long term. For gaming, with the GDDR6X running at 100C or lower, that appears to be within tolerance from Nvidia’s perspective. 24/7 mining on the other hand with memory running at 100-110C seems like the sort of thing that could cause premature card failure.

We don’t have precise answers as to why Nvidia is allowing the GDDR6X chips to hit these temperatures. We also don’t know exactly what “GDDR6X Memory Junction Temperature” means, as far as the other GDDR6X chips are concerned. Presumably it’s the hottest part of any of the GDDR6X chips, measured internally. And again, Nvidia’s cards don’t appear to start throttling GPU clocks until the temperature hits 110C.

If you find your GDDR6X temperatures run super hot with HWInfo64, it’s a good idea to keep your graphics card at stock settings. And if you’re mining, either decrease your power limit or hope that these 100-110C memory temperatures don’t pose a problem. Don’t say we didn’t warn you.

HWInfo64 Release Changes:

• Improved support of some future AMD CPUs and APUs.
• Fixed a possible hang on some systems with Intel Thunderbolt controller.
• Enhanced sensor monitoring on ASUS ROG STRIX B550-XE.
• Added reporting of DIMM module location if BIOS provides correct data.
• Fixed VRM monitoring on ASRock Z490 Taichi and B550 Steel Legend.
• Added monitoring of Effective GPU clock on NVIDIA GPUs.
• Improved reporting of serial number on NVIDIA GPUs.
• Enhanced sensor monitoring on MSI Z590 and B560 series.
• Enhanced sensor monitoring on GIGABYTE Z590, B560, H570, Q570 and H510 series.
• Added monitoring of Aquacomputer farbwerk 360 and highflow NEXT.
• Added fan speed monitoring on some MSI notebooks.
• Enhanced sensor monitoring on some ASRock Z590, H570 and B560 series.
• Added monitoring of GDDR6X Memory Junction Temperature on NVIDIA RTX 30-series.