ufoman

After flashing the modded ultrabay VBIOS my SLI is back in business - thanks all for the work on that! - but I was wondering. Is it safe to flash the modded VBIOS only to the internal card as well? For example, to flash the modded BIOS, then the VBIOS separately, to get the same clocks on both cards? Or should I apply a differently modded system BIOS (modified with the desired VBIOS, naturally?)

Sorry if this has been answered in the thread already, if it has been I missed it. Thanks!

Only modified VBIOS for the ultrabay card is needed. Internal card VBIOS is integrated with the main BIOS and cannot be flashed seperately. This does not cause any issues with SLI, as Nvidia states VBIOS version don't prevent SLI from functioning.

Hi @svl7,

Lenovo recently provided some official vBIOS updates for the Ultrabay GPU's on the Y-series gaming notebooks to allow SLI to work in Windows 8.1. Could you please mod these to unlock the overclocking limit and enable software voltage control like you did for the previous vBIOSes? I've attached the Ultrabay 650M and 750M vBIOSes. Thanks

650M 750M

Reposting for awareness, Win7 ain't being too good for me on Y500.

I am curious as to how the problem lies in the VBIOS if SLI functions in earlier drivers (>=320.49) but not newer ones. I'm not knowledgeable about how the hardware and software interact to cause this problem, but if older software works then it seems like nvidia could patch, rather than requiring Lenovo (and, subsequently for us, svl7) to release updated VBIOS revisions.

I am aware that this is niche enough that nvidia may not know about/decide to commit resources to this problem, as it only seems to affect the Y400/Y500 series as far as my research has seen, but it seems like it would be patchable - anyone know why it isn't? I'm just curious.

320.49 was the last non-WDDM 1.3 enabled driver, that's why the 2nd card starts up on it (but as you know it has an awful lot of problems anyway).

Update. Official BIOS V2.04 update and Ultrabay 650M/750M vBIOS update, which allow SLI to function properly in Windows 8.1, have been leaked. Take a look here: http://forum.techinferno.com/lenovo-ibm/4820-svl7-we-need-you-windows-8-1-a-3.html#post70391

Now all we need is for these files to receive the magical svl7 mod treatment and we're good to go.

happy happy joy joy

chinese leakers and svl7 bring us all hope

I can say that everything works OK with the vbios mod and the ultrabay GPU. Benchmark results appear to be proper, and a fair bit of graphical issues in games related to old drivers are now gone.

Yeah, looks like everything can be in order now - both high clocks and new GPU drivers. I'll report back if my settings from standard p-state overclocking remain stable.

@svl7, any hope for unlocked VBIOS for y500 SLI?

Try with 310.90 drivers, maybe you have similar issue to Guild Wars 2 having totally broken SLI with 313.96 and newer...

I have searched far and wide on Google and it looks like you cannot overclock GPU core on drivers newer than 310.90 (only memory overclocking works in my case). Thus, without the modded VBIOS we are out of luck

Hi,

same problem as song_0814 above. Overclocking works up to 310.90 drivers. I am waiting impatiently for VBIOS mod from svl7