Do Tivo HD's run hotter than S2's?

[WhiskeyTango]

I just got a Tivo HD and popped in a 1TB drive and noticed that the internal temp was running at about 47 degrees. My S2's run at about 32-37 degrees. The THD is on the top shelf of my A/V tower and has less overhead clearance than the S2 below it. The info screen says that 47 is Normal but is that at the higher end of normal or do the HD's just run hotter?

[rocko]

I just got a Tivo HD and popped in a 1TB drive and noticed that the internal temp was running at about 47 degrees. My S2's run at about 32-37 degrees. The THD is on the top shelf of my A/V tower and has less overhead clearance than the S2 below it. The info screen says that 47 is Normal but is that at the higher end of normal or do the HD's just run hotter?

For reference, my THD with a Seagate 750GB drive runs a 46C. The unit sits on a stand with my TV and is totally unenclosed.

[morac]

My unmodified S3 sitting on a table ran hotter than my modified S2 (2 drives, 2 fans) that was in a an enclosed cabinet so I would say yes. The S3 has a faster processor so it would be expected to run a bit hotter.

[NSX]

Yes. All my Series3's run hotter than my S2's.

Although the faster processor may be a contributor, it's not really the main reason why it runs hotter. The Series3 (& TiVo HD) have cooling fans that slow down and speed up depending on the inside case temperature. The old S2's (and probably S1's) had the same fan speed no matter what. I'm assuming this is to keep the S3 as quiet as possible. Reboot your S3/THD and you'll hear the fan at high speed until the temperature control kicks in.

I'm sure someone can explain this better.

[WO312]

Yes. All my Series3's run hotter than my S2's.

Although the faster processor may be a contributor, it's not really the main reason why it runs hotter. The Series3 (& TiVo HD) have cooling fans that slow down and speed up depending on the inside case temperature. The old S2's (and probably S1's) had the same fan speed no matter what. I'm assuming this is to keep the S3 as quiet as possible. Reboot your S3/THD and you'll hear the fan at high speed until the temperature control kicks in.

I'm sure someone can explain this better.
I can attest to the fan speed difference. My Tivo HD used to run about 44-45 C. Earlier this year, I had a lot of problems with the freezing, etc., and in the course of a bunch of experiments, I somehow managed to kill the ability of the fan to run at all when attached to the motherboard. So I had to rig it to run off of the constant 5V from the hard drive, and now it is consistently running about 38C. Tivo apparently wants the machine to run in the mid to upper 40's.

[cdeckert219]

Mine run hotter...
HD in an enclosed cabinet - 48C
HD not enclosed - 45C
Humax S2 (DVD unit) on top of cabinet - 35C

[aaronwt]

I can attest to the fan speed difference. My Tivo HD used to run about 44-45 C. Earlier this year, I had a lot of problems with the freezing, etc., and in the course of a bunch of experiments, I somehow managed to kill the ability of the fan to run at all when attached to the motherboard. So I had to rig it to run off of the constant 5V from the hard drive, and now it is consistently running about 38C. Tivo apparently wants the machine to run in the mid to upper 40's.
Upper 30s or upper 40s, it will run the same.

[janry]

I asked this same question about a year ago about my HD compared to my Series 1. Someone suggested it has to do with the placement of the probe.