July 7, 2010

Optimal BIOS Configuration

Configuring the BIOS is something that almost every PC user had to deal with.

However, it's usually full of terms than even some tech-savvy users don't understand.
This lead vendors to provide a way of choosing "Optimal" settings.

I found out that, even after using Gigabyte "Optimized settings", there's a lot to improve !

With the settings here, we'll tune the PC to optimal settings.

The screenshots below show the actual values we'll get after finishing tweaking all our settings.

From the M.I.T screen, we'll start our tweaking...
Here we see the BIOS version we are running, current CPU and Memory frequencies, temperatures and voltages.

Let's get an in-depth view of the M.I.T Current Status...

We'll start from the Advanced Frequency Settings, to adjust the Memory Frequency.
I'll just select XMP to let it configure all clocks (and memory voltage).
When using an i5, the XMP will also adjust the BCLK and Memory Multiplier to suit best values for both CPU and RAM.

It's important to enable all Advanced CPU Core features.
As, once we started tweaking, the BIOS might Disable some settings if we leave them at [Auto].

Here we see that the BIOS read the frequency and voltage values from our RAM's XMP Profile1.
It's also possible to squeeze a bit more by selecting a different value in "Performance Enhance".
We won't be tweaking any timing here.

We can leave voltages at Auto or Normal.
However, as of the F9 BIOS version, there seems to be a disagreement regarding DRAM Voltage, as if we leave it on Auto, our G.Skill Eco (which is 1.35V) RAM will run at 1.44V.
Not a problem (this RAM can safely tolerate up to 1.65V), but we can make it run a bit cooler with this low voltage, so we select 1.3V (or 1.4V).

Just enable these two.

Here we want to make sure CD-ROM/DVD is not in the list of Boot Devices, as it will slow down the boot process...
And if we later need to boot off a CD ? We can always manually invoke the boot menu by hitting the F12 key.

As with most Hackintosh guides, we want to set the SATA controllers to AHCI mode.

Another Hackintosh classic... Enable the HPET and set it to 64-bit.
If you want WoL (Wake on LAN) to work, you'll have to Enable "PME Event Wake Up".

Here we can see the current temperatures and fan speeds.

After setting all this, we'll hit the F10 key to save and reboot.
The we'll reenter the BIOS, to verify all settings are in effect (it has to recognize the SATA devices using the AHCI mode, etc.)

Good Luck !


  1. Nice to know what to do here without understanding

  2. @Anonymous: Yes, it's been challenging testing the various different combinations, to get to the optimal set.

  3. Mate, I still get slow boot to 10.6.4 with these settings, tried an Intel SSD, a 2.5 inch HDD (WD at 7200rpm) I don't know why booting is so slow, compared to my other mobo using ICH7 chipset. I assume we need both settings to be "AHCI" but do you experience slow boot? If you 'flush caches' in Chameleon (-f) does it take aaaaages to boot, too? Thanks.

  4. @konsti: Are you using a DSDT ? Try passing '-v' (Verbose) to Chameleon to diagnose where it's spending time...

    Don't want to diagnose this alone ?
    Come join us at the tonymacx86 Forum

  5. Dear Lnx2Mac thanks for your advice. I did join tonymacx86's forum, and I am happy that you guys are there to offer some help. It's just that it feels sluggish--I did use the patched DSDT from tonymacx86's blog, on an already set-up drive running 10.6.4 (AsereBLN/proper DSDT/basic kexts) and when e.g. I use -f to flush cache, the lines appearing on screen are so slow, compared to my Q9550 mobo (ICH7) which is darn fast. Is there a category of drives used for GA-P55M-UD4? I use the blue (P55) connectors...
    Tested Win7 x32 and it boots lightning fast...
    Guess I have to post a request in the forum.

  6. @konsti: You shouldn't need -f... Have you tried -v ?
    What do you mean by "a category of drives used for GA-P55M-UD4" ?

    I'm finishing a post on optimal MultiBeast options for the P55M-UD4, so... Stay tuned !

  7. I love this blog! I'm looking forward to your "optimal MultiBeast options" post because I just got my build assembled.

    I was unable to install anything. I could not even run any linux live CDs because they would just freeze at random points. I thought something was wrong with the hardware or had defective memory. I ran memtest and it showed lots of memory errors.

    I set the XMP to Profile1 and all errors went away! I was finally able to run the live CD with no problems, install Ubuntu, and test the system out completely.

    Bottom line: If you get memory errors:

    1. make sure you read this blog carefully
    2. look at the undistorted photos of BIOS screens (either he aligned his camera perfectly or used photoshop)
    3. set the XMP to Profile1!!

  8. @Anonymous: Thanks for your kind words...

    As for Optimal Multibeast, it's up for your delight in Installing OS X Snow Leopard - Part Three...

    Regarding camera alignment, I did my best...
    But the barrel distortion of my 7-years old 3.3MP HP Photosmart 720, set me off to "Perspective Correction" and color "denoising" in Gimp...

    Glad you enjoyed it ;)

  9. I don't see the profile1 option on my bios? I've tried using f9 and f10 and errors abound with both. any ideas?

  10. @Anonymous: Then your RAM probably doesn't support XMP... Which RAM are you using ?

  11. I'm using OCZ DDR3 PC3-12800 Gold Low Voltage Dual Channel (2x2GB) and all the other same options as you. only difference is memory.
    I've tried your steps with both f9 and the f9 dsdt and the f10 and f10 dsdt and keep getting kernel panic.
    Now i can't even get snow leopard to reinstall after a format of the drive. fails mid installation.

  12. @Anonymous: Your OCZs are not spec'ed to run at 1.35V... So you should leave the DRAM voltage as [Auto].
    Undervolting your RAM will definitely cause severe instability !

    You could also run MemTest+ on your rig to verify your RAM is OK, as faulty RAM is very often the cause of instability.

  13. Lnx2Mac, Would you please tell us what hardware you based this guide on? Would some of these settings work with the latest CustoMac 2010 build from Tonymacx86? Thanks for all your hard work!

  14. @Macaddictcr: These screenshots were taken from my P55M-UD4, but should be extremely similar for most P55/H55/X58 Gigabyte boards.

  15. wavesequence from tonymacx86December 4, 2010 at 3:20 PM

    What about XMP for i7 owners?

  16. @wavesequence: If your RAM supports XMP (like my G.Skill Eco), you can select Profile1 under Advanced frequency Settings (as I did).

  17. Hey Great Blog! I was just wondering. I've read elsewhere that you should enable all of the advanced core features except turboboost which they reported actually dramatically slowed down performance. Has this not been your experience?


  18. @SXBB: Thanks for your comment !
    Based on my testings, without overclocking, these are the settings that provide the best results.
    When overclocking, you might have to disable Turbo Boost.

  19. fantastic guide there thanks heaps!

  20. Hello,

    i did the same (loooong study the forums -yours and tonymac- selected the components - P55M-UD4, i5-760, GTS450 and set up the "Optimal BIOS") BUT
    when it starts first round the drives are ok, and it comes in Bios some second round when it says Detect drives, no drive found... and it continues without any problem...
    what is seraching the bios after the SATA section? what kind of drives he do not found...

    it is just annoying not a real problem

    thanks a lot


  21. I put 2x2gb 1600 kingston hx on my pc, but the bios reads them as 1333, how do I fix that? also how do I put XMP as profile1?


  22. @Alex: If your RAM doesn't support XMP, you'll have to manually set-up your Memory Multiplier from 10 to 12.
    Which RAM model are you using ?

  23. hi boys. i have a strange problem. here my specs:
    gigabyte x58a ud3r rev 2.0
    core i7 950
    ram kingston khx1600c9d3k3/6gx 3x2gb 1600mhz

    I followed the guide , system recognises ram at 1600, but on system profiler ram is set at 1333. even if i overclock my cpu at 3,5 ghz, system profiler sets it at 3,07 (stock).
    Someone could help me please? sorry for my bad english

  24. @Anonymous: If your system recognizes it at 1600MHz, then you shouldn't worry.

    It's probably an issue with Chameleon, and it should be just cosmetic.

  25. Lnx2mac thank you very much!
    how can i understand if the ram is going at 1600 on mac osx? so i can get sure that it's only a cosmetic problem. i'm using multibeast 3.0 obviously with ati experimental as boot loader

  26. @Anonymous: As MacMan stated here, "There is a know bug in Chameleon RC5 with incorrect RAM speeds being displayed on X58 systems in OS X".

    To verify it's just cosmetic, run GeekBench, then set RAM in your BIOS to run at 1333MHz, and rerun GeekBench... You'll see the difference ;)

  27. thank you, that's why even my cpu clock is seen at 3,06 instead of 3,20.
    thank you so much

  28. Hey Great Blog! Thanks for the Realtek driver too!
    I've read in other places that intel turbo boost can actually dramatically slow down a Hackint0sh. I have an i5 750 USB3 rev2 with 8g of 1600 ripjaws. Do byou think Turboboost would be good for me to run?


  29. @SXBB: Thanks for your comment !

    Regarding TurboBoost, as long as you are not overclocking, there shouldn't be any adverse effect to it.

    But don't take my word for it...
    Record your current settings, benchmark, and try with other sets of values... Experiment !... ;)

    Note that as you are using an i5-750, to get the RAM to run at 1600MHz, XMP is slightly overclocking your CPU.
    So it will be interesting to see which results you can achieve... Please report back.

    Good Luck,

  30. had an issue with wake from sleep, if it sleeps for a long period it struggles to come out of sleep and gets stuck in a loop.

    I need to then hard power the machine off, could this be RAM or C1E state related?

  31. Can you recommend Ram settings for a GIGABYTE GA-X58A-UD3R MB and CORSAIR XMS3 12GB DDR3 1333 ram? It would be extremely helpful with my new build. I am not sure if I have to change anything or change everything from voltage etc. Please let me know and thanks.

  32. @Tom: Isn't your RAM being detected at 1333MHz ?
    If it is XMP compliant, then it's recommended to select Profile1 in Advanced Frequency Settings.
    Otherwise, you might need to manually modify the System Memory Multiplier (SPD) so that BCLK * SPD = 1333

    You should not lower DRAM Voltage unless using G.Skill Eco modules.

  33. Well I am currently waiting for the rest of the parts to arrive then I will let you knows my results. I was just trying to prepare ahead. My ram is not XMP compliant and my Motherboard supports up to 1066 without OC. I may first leave the ram settings and set up the Hackintosh, then later try to run it at 1333MHz.

  34. @Tom: As you are using non-XMP RAM, you'll have to manually configure the SPD, as I wrote above.

    Then read a few comments up, where I linked to "Not Shy's guide to RAM testing", I strongly recommend you following it to ensure your hardware is OK.

  35. Hi alltogether,

    just a note on changing RAM voltage as I had an issue with my gigabyte P67A-UD7 F4 doing this.

    The computer didn´t start anymore, not even into BIOS, black screen only and ended into an endless loop of start up/shut down at approx. 10 second intervall. I forced it to shut down and at a later stage was successful to boot into BIOS again.
    And there I got a BIOS warning stating that there had been boot failures caused by overclocking (which I didn´t) or changes of voltages (that´s what I did as described in the blog).

    After changing the values back to AUTO the issue was resolved.

    Well, it´s still the F4 BIOS, but I can´t check the F6 yet as I can´t make the board (or rather Qflash) recognize the USB stick with the unpacked BIOS. This behaviour is strange also, as I remember the USB stick beeing recognized when I did my first steps into BIOS according to lnc2Mac´s tutorial.

    Looks like I still have to do quite a lot of homework...

    Cheers, and thanks to all of you guys sharing all this stuff!

  36. @Say Heading:
    Regarding RAM voltage (and timings in general), you should always check what are its specs. The values I posted are for the G.Skill Eco.
    As for the QFlash issues, doesn't it recognize the flash update file ? Or the USB stick ?
    Have you checked my posts on unpacking and updating the BIOS ?
    Good Luck,

  37. Thanks for this. I don't have XMP compatible memory but for me the bonus is knowing not to have CD-ROM in the boot list (I currently have it as my second device. It shouldn't make any difference if I remove it because the HDD is the first boot device... but I'll test.)

    One thing I have discovered is that you need to DISABLE C1E if you use SSDs as this significantly reduces performance.

  38. Thanks! Changed everything but the DRAM Voltage, and went from a GeekBench (32bit test) score of 8769 to a 9006.

    Here are some of my specs:
    - OSx 10.6.7
    - Intel i7 950
    - Corsair 12GB ram

  39. Hi, I got a really strange problem.

    I got a X58A UD3R Bios FF and almost everything is working. But my system clock is always running ahead of time, means faster, especially if there is a high CPU load. VLC stutters when playing back audio.

    Help would be apreciated.


  40. @Anonymous: Did you install from a Purchased Retail Mac OS X Snow Leopard DVD ?

    Are you using a DSDT ?
    I recommend you to grab one for your board/BIOS from tonymacx86's DSDT database.

    Are you using the Vanilla kernel ?

    Also, older versions of Chameleon had many of these fast-clock issues...
    Do you have busratio= on your kernel flags ?

  41. Hi Lnx2Mac,

    yes, purchased OSX, yes dsdt from tonymacx, matching revision and bios version. vanilla kernel also.

    i will try to change the chameleon, currently i have 2.0 RC2-640. will try to get a newer one.

    what do i have to do with the busratio= flag?

    by the way, restarting does not work, but shut down.

    thanks for you answers


  42. Lnx2Mac, you are the man! All my problems were cause by the old Chameleon. I replaced it with the 750 and now everything works completely smooth, including restart etc.

    Thank you so much!


  43. @Thomas: Glad it helped !
    As for busratio, if you had it, that could have been another cause for your problems ;)

  44. Is there any way to avoid the AHCI setting in BIOS, I get OSX working 100% but this takes a while to load. (After BIOS splash screen I get about 3 seconds of AHCI screen, or more).

    I'm looking for a way to speed this up and integrate the apple logo in the BIOS (I know that can be done), I just don't know if it's possible to speed up the AHCI process.

    Thanks for the guide, very helpful!

  45. @Anonymous: I don't know of a way to speed-up the AHCI detection.
    Are you using the latest BIOS available for your motherboard ?

  46. Yes, however I've been searching for this for quite a while now and I don't think it's possible.

    So I'll just leave it as it is, and try to ignore it :)

    Anyways, thanks for the great guides and RTL driver!

  47. Are these optimal settings geared towards that particular motherboard you are using? Or is this guide universal, regardless, even for Z68 boards as long as its by Gigabyte?

  48. @Anonymous: While these were done on a P55M-UD4, the settings here should match all/most Gigabyte P55/H55/X58/Z68.
    You'll probably find some new settings but most of the ones here should be right for you too.

  49. Lnx2Man-
    My Custom Hackintosh build is up and running but I am having an issue when I try to install the fourth stick of RAM into the slot. I have tried all of the slots independently and they work but, when I try to add the the last stick my machine will just start to turn on, and then turn off. If I were to let it, it seems like it would just keep turning on and off indefinitely. Any suggestions?

    I have had nothing but bad luck at the tonymac site. I was forwarded the link to your blog today so I am going to try your settings, hopefully it will help with my slow boot time.

    GIGABYTE GA-Z68MX-UD2H-B3 LGA 1155 Intel Z68 HDMI SATA 6Gb/s USB 3.0 Micro ATX Intel Motherboard
    Intel Core i5-2500K Processor 3.3GHz 6 MB Cache Socket LGA1155
    GIGABYTE ATI Radeon HD6870 1GB DDR5
    Corsair Cooling Hydro Series H50 All in One High-performance CPU Cooler CWCH50-1
    PC Power and Cooling Silencer 760W High Performance 80PLUS Silver SLI CrossFire ready Power Supply compatible with Intel Sandy Bridge Core i3 i5 i7 an
    PX-LB950SA Internal Blu-ray Writer
    OWC 254GB SSD
    Corsair Vengeance Blue 4 GB PC3-12800 1600mHz DDR3 240-Pin SDRAM

  50. @ramettacard: Could be a defective motherboard or RAM stick.
    Just to be sure, this is without overclocking, right ?
    And using stock (auto) RAM voltage ?