DDR3 & GDDR5 temperature monitoring

Assiduous

New Member
Hello Martin,

My compliments to you on a very good bit of software :)

I'm interested in monitoring my DDR3-RAM temperatures (ASRock Z77 Pro 3) and my GDDR5 VRAM temperatures (AMD R9 270). I have seen other posts indicating that you have added the capability for reading RAM temperatures. The SPD readout indicates module temperature sensor is not supported, however I note you have posted previously that "The Module Temperature Sensor (TSOD) flag is set by the module manufacturer and it often doesn't reflect the reality, so one can't rely on this". Accordingly i have attached some dbg output...

Regarding GDDR5 on die temperature sensors. The data sheet for my GDDR5 (EDW2032BBBG) confirms each chip features an on-chip temperature sensor with read-out. MY GPU contains 8 such chips.

The JEDEC GDDR5 standard (pg 104) states that the temperature readout uses the DRAM Info mode feature. The digital value is driven asynchronously on the DQ bus following the MRS (mode register set) command to Mode Register 3 (MR3) that sets bit A7 to 1 and bit A6 to 0. The temperature readout will be continuously driven until an MRS command sets both bits to 0.

DRAM Info
Bits A6 and A7 enable the DRAM Info mode which is provided to output the Vendor ID, or optionally the
current junction temperature or other vendor specific device info.
The Vendor ID identifies the manufacturer of the device, and provides the die revision, memory density and
FIFO depth.
The Temperature Readout provides the SGRAM’s junction temperature. Vendors may require that the
related on-chip temperature sensor being enabled in advance by bit A6 in MR7.

Temperature Sensor
The optional on-chip temperature sensor is enabled by bit A6. DRAM vendor may also have the on-chip
temperature sensor enabled permanently; in this case bit A6 is “Don’t Care”. A detailed description of the
Temperature Sensor can be found in the VENDOR ID, TEMP SENSOR and SCAN section.

Are you able to add this to HWinfo? GPU-z and ASUS memory info can access the vendor info but they didn't take the extra step of reading out temperatures.

1610452924414.png

Regards!
 

Attachments

  • HWiNFO64-dbg-DDR3.txt
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Martin

HWiNFO Author
Staff member
I'm aware of that GDDR5/6 feature to report parameters including temperature.
The problem here is that this information is exchanged internally between memory modules and GPU (IMC), so it requires some interface to provide this information to other clients. While AMD offers such interface for later GPUs, NVIDIA is keeping this secret. I'm not aware of anyone that would be able to figure out how to read the GDDR temperature on NVIDIA GPUs yet, but maybe it will happen one day...
 

Assiduous

New Member
Thanks Martin, I have made a service request to AMD to provide us with the required interface for GDDR5 temperature monitoring. I'll be in touch if they come through.
 

Martin

HWiNFO Author
Staff member
AMD provides this for later GPUs, but NVIDIA doesn't (or rather keeps this secret).
 

Assiduous

New Member
No response from AMD unfortunately beyond suggesting posting on the developer forum - going to need some support. There are many GPUs out there with GDDR5; if you would like the ability to monitor GDDR5 temps, then please show your support for my post over at the AMD developers community forum - https://community.amd.com/t5/devgur...-chip-temperature-monitoring/m-p/439890#M4029

You can also send your own service request to AMD and reference my request - {ticketno:[8201047329]}
 
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