de-zwaluw

@Klem Nice stuff, thanks! I was able to run the second GPU OC'd to 250MHz, but past that (at least in Bioshock Infinite benchmark) stuff crashes. I notice that voltages for my internal GPU run higher because of unlocked voltage offset, so I guess I would be able to push to +400MHz for second GPU if voltage was unlocked here too. Please unlock this or set it to +200mV like I have for my internal GPU!

So does that indicate that Lenovo has done something to Windows in such a way that once Intel drivers are installed, stuff completely breaks down unrecoverably unless clean install?

I have actually deleted the BT driver that comes with the computer and let Windows install generic drivers. That makes BT stuff connectable, but since BT completely disappears after the laptop awakens from sleep, it's quite useless. Or maybe I should learn to switch off laptop every night since I use an SSD...

It has probably been answered elsewhere, but since we're on the topic of crappy bluetooth support on this laptop, has anyone tried swapping the default Wifi module for the Intel 7260 with BT? Does it solve any problems? I'm planning to put the 7260 into my laptop (mainly for ac), and although I don't care much for BT, it would be nice if it actually worked.

Yes, I know factory image isn't as good as fresh install. The problem is I don't have any medium right now to fresh install Windows. The disks I have don't seem to work and I couldn't be bothered looking up a torrent. Lenovo doesn't have much bloatware anyway, and I have uninstalled everything I don't want. But the reinstall of Windows 8.1 had nothing to do with factory image, and my point was that Windows 8.1 update didn't like the second GPU's new VBIOS.

I recently restored my Y500 to factory image and tried to install Windows 8.1. The update kept failing over and over again (with error 0x80004005, apparently something to do with drivers), until I removed the second GPU from the ultrabay. So that might be something to take into consideration!

Subpar? Imho, the Y500 has one of the best cooling designs I have seen in a laptop, not to mention the (well, my) laptop generally stays completely silent in non-demanding tasks, such as browsing and typing. Even when I have the internal GPU overclocked to 1200MHz and the CPU and GPU are under pressure (e.g. in a game), I seldom reach more than 70 degrees C. That's not bad at all!

Since the problem is with SLI in Win8.1, you should flash it within 8.1. But I don't know if it makes any difference if you flash it within 8.0.

Thanks! Great to gear that Lenovo finally has released an official (non-Chinese) VBIOS! I just re-flashed with that one, just in case there are any improvements, though I highly doubt it. But why not.

Thanks to UltimaClaud, I managed to flash both my Y500's BIOS and the VBIOS of my 650m ultrabay! Not sure if there'll be any difference at all when Lenovo outside China releases a VBIOS, but the files UltimaClaud linked work like a charm! Anyway, got the BIOS and VBIOS files from this entry, and then I had to apply a little of my own experimenting skills, using stuff from various threads and webpages. Below is a copy-paste from another thread on how I did this. Got it working by downloading the files (BIOS v2.04 and vbios650sli), creating a DOS bootable USB stick using Rufus and downloading the latest NVflash for DOS. From the latest NVflash zip, I took the files CWSDPMI.exe and NVFLASH.exe and replaced the ones in the unzipped VBIOS folder from Sendspace (otherwise I got a "Cannot be run in DOS mode" while trying to flash), and dumping all the files into the root directory of my DOS ready USB stick. Restarted > F2 > Boot > Boot Mode: Legacy support > save and exit. I did have to turn off EEPROM write protection using nvflash --protectoff for the flashing to work. Then I flashed the VBIOS by typing "nvflash -i1 -6 7003A.rom" (i1 indicating the ultrabay card). (more on flashing VBIOS here) Works like a charm, tried it with some basic overclocking in Metro: Last Light! Check it out. Latest NVidia drivers and stuff too.

AWESOME STUFF! Thanks a bunch! Got it working by downloading those files (BIOS v2.04 and vbios650sli), creating a DOS bootable USB stick using Rufus and downloading the latest NVflash for DOS. From the latest NVflash zip, I took the files CWSDPMI.exe and NVFLASH.exe and replaced the ones in the unzipped VBIOS folder from Sendspace (otherwise I got a "Cannot be run in DOS mode" while trying to flash), and dumping all the files into the root directory of my DOS ready USB stick. Restarted > F2 > Boot > Boot Mode: Legacy support > save and exit. I did have to turn off EEPROM write protection using nvflash --protectoff for the flashing to work. Then I flashed the VBIOS by typing "nvflash -i1 -6 7003A.rom" (i1 indicating the ultrabay card). (more on flashing VBIOS here) Works like a charm, tried it with some basic overclocking in Metro: Last Light!

Hmmm, who to blame.. Lenovo or NVidia? So until either of these or someone else can fix it, nobody has SLI? How lousy.