Clarify state of T/W switchable graphics for Win7

Just to clarify, are the following switchable graphics issues still present using the latest (as of April 8, 2010) T500 drivers?

1) Increased power consumption suggests that both integrated and discrete graphics are running.
2) Unable to change display brightness when using discrete graphics.
3) Enabling switchable graphics reduces the usable amount of ram in a 32-bit system from 3.25 to 2.46 GB.

I know (1) can be corrected by toggling from integrated to discrete to integrated again. The latest switchable driver claims to fix (2) but (at least in my case) doesn't. I'm not sure if (3) is a side-effect of switchable graphics or a driver problem.

I've installed the latest Hotkey driver, Power Management driver, Power Manager, and display drivers (I even tried the leaked "Catalyst 10.5 beta"), but the above problems still persist. I've searched previous threads, but those that fixed their issues seem to have done so by accident/luck. I can't find an update/upgrade path that will conclusively solve the three issues above. Did I miss something?

 

Regarding #1, that issue is still not fixed, unfortunately. ATI's beta drivers that support switchable graphics also have the same problem, funnily enough.

I do not have problem #2, and I run Windows 7 Professional 64-bit, so I do not know whether #3 is a widespread problem.

 

Thanks MidnightSun.

I just learned that it is possible to adjust display brightness from the Lenovo Power Manager and the Windows Mobility Center (Win+X).

With Lenovo's drivers, neither method works. However, with the Catalyst 10.5 drivers, both work (but still not the Fn+Home/End). This show promise

 

I have no problem with adjusting display brightness using Fn+Home/End with Lenovo SD drivers.

Excessive power use with integrated gpu remains a major problem. With Vista I used integrated gpu most of the time; with Win7 I use the dedicated gpu most of the time.

I use Win7-32bit because the I found SD drivers for 64bit are inferior to the 32bit ones.

 

Wow, I seem to be the only one still suffering from issue (2)! I wonder what I'm doing wrong/differently.

When I first boot the ThinkPad, pressing Fn+Home/End displays the brightness OSD. If integrated graphics are in use, the screen brightness also changes. If discrete graphics are in use, the screen brightness does not change (despite the OSD readings).

Once I sleep, hibernate, or switch graphics, the brightness OSD never appears again (though, the volume, etc. do). Again, changing brightness is only successful with integrated graphics.

I've also used System Update to download/install the Windows hotfixes related to handling keyboard events -- no change. The only update I haven't performed is for the BIOS. Considering the BIOS update release notes don't mention any of my issues, I decided to not risk a bad flash.

 

Update: I now realize how to solve issue (2).

Although the latest version of the switchable graphics drivers (7vd614ww) claims to fix the issue of adjusting screen brightness, the solution might also require a BIOS update. My BIOS (version 2.12) did not officially support Windows 7 (support was added in version 3.06). So, I updated to version 3.13 (the latest one) and am now able to use Fn+Home/End as expected.

I try to avoid BIOS flashing and the BIOS release notes never mentioned this specific fix, but anyone else experiencing the inability to adjust screen brightness should flash their BIOS to the latest version (or at least one with Windows 7 support).