(UEFI) Dell XPS 15z L511z modded BIOS - and HOWTO

[TimeWalker]

I would actually udservolt or underclock mine rather than OCing it, but its good to know you have finally figured a way.

[thorbsd]

Glad you finally figured out how to OC!

I don't suppose any of you guys have ever tried figuring out how to disable Optimus, or switch to using just the nVidia GPU?

I recall that the option was in the BIOS, but apparently it didn't seem to do anything.

[TimeWalker]

You can't just switch to nvidia as it only renders stuff and outputs thru uma, acts like an acceleralor and is not physically connected with lvds, but can be with other connectors (take HDMI on 15r as an example). Disabling nvidia completely can be done by means of dsdt, but we don't know how to reintegrate it properly to avoid black screen. But then again, disabling it may result in some port loss.

[jkbuha]

5% O/C seems to be on the low side. With Clover I can push up the FSB easily to 120MHz (with corresponding increase in performance) without any issues. True it's OSX - I still havent figured out how to boot Clover into legacy Windows without having to reinstall Win8 UEFI, but maybe the high o/c is because the i7 has a wider spread spectrum than the i3.

Just out of interest, not sure if you have OSX installed, but if not could you boot up a linux livecd and check if you can get higher speeds?

[kasar]

well

the only think I can tweak for now is the BCLK/DMI/PEG line, and I didnt saw too much people going over 105

for example

http://www.legitreviews.com/article/1650/17/

also your i7 have turbo boost, wich let you to play a little with the multipliers I think, my I3 doesnt have that D:

I can only play lowering the ram frecuency at the bios lowering it, but I dont think the ram speed is limitating wich such low OC


take in mind even that minor tweak messed up my apps timming, and I had to use some tools to fix the timmings on windows.

and no, I dont have OSX

[kasar]

mmm, any of u guys interested in more ME firmware tweaking?

there are some stuff I read on the intel documentation

aparently there are two types of firmwares

production, and non production

I supose non production firmware is like pre production firmware with unlocked stuff.

my firmware dump (the one I sucesfully modded to BCLK OC) is production I think, while editing it, it seems to have lot of greyed options.

also, I have some questions.

what is the difference between BTM (Buffer Through Mode) and FCIM (Full Clock Integrated Mode) in terms of Overclocking?

my laptop is currently running at FCIM mode, I was wondering if is posible to change that mode through ME firmware and or descriptor, since I saw options at FCIM to change it.

well, I am happy with my BCLK unlock, but I was wondering if there are any way of unlocking more OC options like CPU dividers

for examples the ones asked at this post

http://hwbot.org/newsflash/1441_how_to_o...y_bridge_e

not sure if I can do all of that with my current chipset/proccesor

but I still interested on get out the max posible from this laptop and OC it to the max

[jkbuha]

Interesting article - seems also to explain why, with a locked ME you can theoretically clock up to 125-135MHz FSB, which roughly equates to what I found with Clover+OSX. Interestingly I also had the timer calibration issues you noticed - at 115MHz my system clock started to behave erratically and I had intermittent audio, so would be good to see if we can recalibrate on OSX as well.

As with TW, I'm more interested in undervolting than o/c'ing - my battery is starting to decrease in capacity, and if I decide to replace it I'll probably do that once we've figured how to reduce the base VIDs for our SNB motherboards.

Also over the last week my 1080p LCD screen has developed an annoying screen bleed which apparently is a known defect on these WLED truelife screens. It seems to be increasing so most likely I'll have to get a screen replacement as well - which brings me to why I've posted it here...if I find a cheapish 2560x1600 or 2880x1800 15.6" screen with a right-side 40" connector, using our new unlocked v2158 bios it may be a good idea to think about a naughty mod upgrade

[kasar]

:o, then I am not done yet

yeah, if you was able to reach that high OC, without even touch the ME, there must be something else I can do with mine.



can you post your OC info?

like what is your current proccesor.

its stock proccesor speed (with no turbo)

and the values you modded with also the final cpu frecuency after OC

also all people said you cant mod the BCLK over 105 without issues on most motherboards because it also mess another timmings like sata, pcie and other stuff.

I must be missing something

it is funny to know that the 15z wich is like a simple and slim xps 15 without some features included improved cooling have better OC than mine

[jkbuha]

To be fair mate, it's comparing apples and oranges for now, as you & I have done it through two different ways. Hopefully you'll manage to boot up OSX using your method and run geekbench in the same way I did, or even better, I manage to soft-mod the ME and/or boot up Win in UEFI mode via clover as well

So here are my stats:

i7-2620m (dual not quad processor) - 2.7GHz stock speed, 3.4GHz with turbo.
O/C'd with Clover to 125MHz bus speed (ie: 25% o/c) - now running at 3.375GHz stock, 4.0GHz turbo

Geekbench Score:
100MHz FSB -> 7415
125MHz FSB -> 9242

Otherwise everything seems to be running fine @125MHz FSB. Important to note that FSB (not only Turbo) is increased, so in theory you should see similar performance increases.

[kasar]

the problem is that having almost the same hardware , I can only do 105 bclk while you get 125 without issues.

you must be locking some hardware clocks wich interfers with bclk so u can push it higher.

I must to know what are your hardware clock settings, so I can replicate your settings and make a modded ME image so I can OC natively any OS.

clover isnt working for windows 7, thats why it doesnt seems a valid option for me.

if a piece of software like clover can do cool stuff like that, then must be a way to make it too with ME, BIOS or even other software :o