fan behavior comparison of T42 and T43

[danda821]

I did some comparison between the two models.

T43: 2G CPU, 256MB memory, 7K100 80G, fpr, SXGA+
T42: 1.8G CPU, 512MB memory, fijitsu 5400 80G, fpr, bt, SXGA+
Both use fan-control, no NHC

1. fan speed (I use fan-control test the fan speed)
a. T43
level 1: 3200 rpm; level 2: 3276; level 3: 3800; level 4,5: 3875
level 6,7: 4357
all audible at normal sitting position
b. T42
level 1: off; level 2:3000; level 3: 3603; level 4,5: 3720;
level 6: 4204; level 7:4224
audible from level 3. I feel the sound of level 3, 4 is equivalent to the
sound of T43's level 2

Under BIOS control, the fan of T42 starts when CPU temperature is higher than ~46C,off when lower than 42. So T42 fan also often turns on (like T43).But the sound (level 2) is not audible.

2. computation speed
I use super-pi to do the comparison. Since T43 only has 256MB memory, I choose a small size computation -- 1M digits
T43: 40s; T42: 46s

3. temperature and fan behavior during 16M computation
use super-pi compute to 16M digit
a. T43
CPU: 49 APS: 43 PCM: 33 GPU: 47 BAT:32 BAT:26 BUS: 44 PCI:45 PWR:44
fan speed: 3728 (audible, noisy)
after computation, when fan stop:
CPU: 41 APS: 39 PCM: 33 GPU: 41 BAT:28 BAT:24 BUS: 36 PCI:42 PWR:39
b. T42
CPU: 59 APS: 43 PCM: 30 GPU: 53
fan speed: 2947 (not audible)
after computation, when fan stop:
CPU: 43 APS: 39 PCM: 29 GPU: 43

though the temperature reading of T42 is higher than T43, the bottom of T42 feels cooler.

4. fan behavior when using real player
a. use fan-control v0.18 and default value
T43: fan turn on for 1min, then off for 3min, then on ...
T42: fan turn on for 0.5min, then off for 2min, then on ...
b. under BIOS
T43,T42: fan on all the time

So the fan behavoir of T42 and T43 is similar, except the fan speed of T42 is much lower and not audible, and it does stop sometime. As techinical support of IBM said, both machines are designed to have fan on most of the time. The only difference is fan T43 speeds faster since sonama has more heat.

I even open both machine, the fans look identical (both are long fans). Except the one in T43 has a silicon pad contacting the bottom of the key board to help get rid of heat.

Anyone know if lenovo will give a BIOS update to make the fan slower?

[merlin]

My t42
Level 1.2 2909 RPM
Level 3.4 3395 RPM
Level 5 3419 RPM
Level 6.7 3941 RPM


Are you sure of 0 Level of Level 1

[danda821]

I check it again. You are right. level 1 = level 2