Support in other languages: 
Reply
Token Ring
middleton
Posts: 160
Registered: ‎10-30-2009
Location: Russia

Re: Ideapad U350 Fan Control / Speed

Here is some details about the patch (BIOS version 1CCN26WW).

First of all temperature tables, in Celsius (BIOS file offset 0x9BAC):

 

1)

50 - 45

57 - 50

65 - 55

73 - 65

85 - 75

 

2)

50 - 45

57 - 50

65 - 55

73 - 65

80 - 70

 

3)

44 - 40

49 - 45

52 - 47

54 - 49

64 - 55

 

4)

60 - 55

60 - 55

60 - 55

70 - 60

76 - 65

 

5)

70 - 60

70 - 60

70 - 60

80 - 65

95 - 80

 

6)

00 - 10

55 - 50

60 - 55

65 - 60

70 - 65

 

7)

68 - 65

68 - 65

82 - 46

86 - 75

90 - 80

 

Each table is divided on 5 intervals. The first number in each interval is the upper limit, the second one is the lower limit.

When temperature intersects the upper limit, we automatically move into the next interval. When temperature intersects the lower limit, we go down into the previous interval. Fan speed is changed only when temperature intersects any limit, while temperature is within interval - fan speed is not changed.

 

Now about two fan speeds tables (BIOS file offsets 0x9C66 and 0x9C7E)

 

1)

FFFF

02CE

028D

0246

020E

01EA

 

2)

FFFF

01D5

019F

017A

015C

0138

 

Each table contains 6 speeds. Fan speed is driven by PWM (Pulse Width Modulation). The first byte of speed value is PWM base frequency divider, the second one denotes the duration of zero level in PWM impulse (0x00 - duty cycle is 100%, 0xFF - duty cycle is 0%). Lets take two values for example:

 

FFFF - the fan is completely OFF;

02CE - the base PWM frequency is divided by 2, duty cycle = 100% - 100% * (0xCE / 0xFF) = 19%.

 

So how does all this stuff work? Assume that U350 firmware uses the first temperature table and the second fan speeds table. In that case we have the following correspondence between temperatures and fan speeds:

 

50 (01D5) - 45 (FFFF)
57 (019F) - 50 (01D5)
65 (017A) - 55 (019F)
73 (015C) - 65 (017A)
85 (0138) - 75 (015C)

 

And finally what I did in the latest version of the patch. I changed two fan speeds tables:

 

1)

04E0

04E0

04E0

04E0

04E0

01EA

 

2)

04E0

04E0

04E0

04E0

04E0

0138

 

According to testers, the fan rotates at almost inaudible speed all the time and turns on full throttle only if CPU temperature is above 55-60 degrees in Celsius.

I hope using this information you can tune up the fan the way you want (if my patch doesn't suit you).

Punch Card
xloserx
Posts: 65
Registered: ‎10-27-2009
Location: Norway
0

Re: Ideapad U350 Fan Control / Speed

The fun thing about having the fan on at almost inaudible speed all the time is that temperatures are much lower than before I tried your great modded BIOS, Middleton.

As so many times before; it once again had to take someone outside Lenovo to clean up their mess.
Paper Tape
Krasher
Posts: 5
Registered: ‎11-02-2010
Location: USA
0

Re: Ideapad U350 Fan Control / Speed

Same experience here - temperatures are lower than before.

Paper Tape
Loch1985
Posts: 2
Registered: ‎11-03-2010
Location: Germany
0

Re: Ideapad U350 Fan Control / Speed

hi

 

tested the modded bios and it works perfect.

 

i used prime95 stress test my cpu and the fan kicked full speed in at 65°C (used CoreTemp to read temp.)

 

i have the model with Core Duo U4100

 

i edited the DSDT tabel myself but had no luck so thx i´ve alrady given up hope :smileywink:

Paper Tape
shiretzicu
Posts: 1
Registered: ‎11-04-2010
Location: Romania
0

Re: Ideapad U350 Fan Control / Speed

Thanks a lot Middleton you did a great job ! Can u tell what is the difference between the two versions you posted ? Also guys for those of you who didn't find out until now Synaptics released a new driver which enables two finger scrolling. Sry for offtopic hope it helps...

Token Ring
middleton
Posts: 160
Registered: ‎10-30-2009
Location: Russia
0

Re: Ideapad U350 Fan Control / Speed

The first version is just the initial one (the fan is quieter than in the official BIOS but still quite audible).

The second version (recommended for flashing) was created as a result of feedback from U350 owner.

Paper Tape
Viper3062
Posts: 6
Registered: ‎11-04-2010
Location: Germany
0

Re: Ideapad U350 Fan Control / Speed

[ Edited ]

HI, i actually downloaded the file but i cant install it. I tstarted it with the amdinistration righst but it still produce a error msg.

 

Do i have to download some mor efiles? or what can i do? need some help pls

 

 

EDIT: "cannot load driver" error msg ?

 

i still installed the BIOS Uodate from the official LENOVO site before.  Is there any  competitive beetwen your new bios?

Paper Tape
Viper3062
Posts: 6
Registered: ‎11-04-2010
Location: Germany
0

Re: Ideapad U350 Fan Control / Speed

Hey, it works !! =)

 

Forget my last question, only restart was needed.

 

Thanks for this great Bios MOD !!!!!

 

You're my Hero

 

Grretz @all U350 Users

C-K
Paper Tape
C-K
Posts: 1
Registered: ‎11-04-2010
Location: Germany
0

Re: Ideapad U350 Fan Control / Speed

Hey,

 

I just wanted to let you guys know that I've got my U350 today and have experienced the fan issue as well. After having read this thread I first considered opening up the body and looking for the sticker on the cpu, but fortunately I continued reading and tried middleton's bios-fix.

 

What can I say? It's working out great and I can't thank you enough for your effort, middleton! Lenovo should send you a check with a generous number on it.

 

Thanks alot,

 

Chris

Paper Tape
Krasher
Posts: 5
Registered: ‎11-02-2010
Location: USA
0

Re: Ideapad U350 Fan Control / Speed

They should send all of us checks for wasting our time over this and for being so obnoxiously unresponsive.