Wondering about temperatures during surface test

[Luis]

Hello,

I routinely run the surface test on my 2TB external drives to double-check that everything's okay, and it's quite common for my drives to hit temperatures around 49°C while the test is running. My drives are more than 50% full, so the test can sometimes take almost 4 hours to finish...and for 2½ of those hours, temperatures hover around 49°C. Now, my external drives are WD, and from what I understand they can sometimes read a few degrees higher than their actual temperatures...but my question is: how many hours can an external drive sustain 49°C before it becomes an issue? Surely 2½ hours during a test is not enough to overheat things so much that its lifespan is irreversibly shortened, correct?

Besides routine usual surface tests (which I've only run about 5 or 6 times in the past), my drives never reach anything higher than the late 30s or so. For reference, when I first connect them to my PC, they're usually around 23°C before I start the test. Like I said, everything's fine with my drives...I'm just wondering if high temperatures are considered more or less safe as long as they do not progress past yellow. Obviously, once they hit the red zone, that's bad...but according to everything I've read, as long as it's not higher than 50°C, everything should be fine. It's surprisingly difficult to find any definitive material regarding the effects of internal heat on external HDDs, just a lot of anecdotal stuff. Again, my drives only hit temps of 49°C or so during tests, and that's only for 2½ hours before they eventually cool down.

It's probably a dumb question, but as I've said: I have no idea how many hours of heat are considered dangerous.

[hdsentinel]

If your drive reaches 49-50 Celsius only during a long, intensive test and normally (when the drive does not perform any actions, so idle) it works around-below 40 Celsius, then it is fine, no need to worry.

Ideally yes, we should try to keep the temperature lower, but in a small, closed external hard disk enclosure this is not really possible many times. Reaching 50 Celsius generally rarely and for relatively short periods of time is acceptable.

Some people place laptop cooling pad under the external hard disk drive(s) to try to cool them at (least with some Celsius). If you prefer, you can give it a try (or try to position a fan) to cool down the drive under intensive use too.

[Luis]

Yeah, it only reaches 49°C or so during tests, and that's only for a period of 2½ hours. Like I said, I've only run the surface test about 5 or 6 times, over a period of a few months. So unless I'm totally wrong, 49°C for 2½ hours less than a dozen times does not sound TOO intensive. I will definitely look into those cooling pads, though.

So, just to be sure: what would you personally consider a "brief" period? Anything less than 3 hours? 4? I am just trying to figure out what to avoid as there isn't a whole lot of specific information regarding internal heat/hours of exposure.

[hdsentinel]

Acceptable if it's relatively short compared to the total use/life of the drive.

I mean if the hard disk drive works around 40 Celsius for an entire week/month except this 2½ hours period (when the temperature goes up to 50 Celsius), then it can be fine.

We can check the specs of the actual model to be sure, but usually 50 Celsius is the absolutely maximum limit. So (at least now, even during the tests) your drive was operating at slightly lower temperature than the absolute maximum.
Additional cooling can help to have more "room" especially when the room/office temperature may increase in the summer period.