Modifying BIOS for Dell Optiplex 755 / overclocking with RW Everything

Discussion in 'BIOS Mods' started by MarkConstantine, Apr 7, 2015.

  1. MarkConstantine

    MarkConstantine MDL Novice

    Apr 7, 2015
    #1 MarkConstantine, Apr 7, 2015
    Last edited: Apr 8, 2015
    Hi everyone. I hope this is the correct place for this thread. If not my sincere apologies.

    In brief

    -Manufacturer: Dell
    -Machine: Dell Optiplex 755
    -Motherboard Model:
    -Bios revision: A22 (full filename O755-A22.exe)
    -Bios Type: Dell Phoenix BIOS
    -Bios Download Link: h t t p : / / d o w nloads .dell .com/FOLDER01133147M/1/O755-A22.exe
    -RW Everything Report Download Link: h t t p s : / / www . mediafire . com / ?sws38tp821abyos

    Longer version

    I've spent most of today browsing this and other sites learning about how to customise a BIOS, and I'm a bit stuck now. I hope someone would be kind enough to help me.

    What I'm trying to do

    I'm a hardware engineer working for a small charity. We collect, process and reuse or recycle IT equipment from various places, and then supply this equipment at low cost to other charities and non-profits around London. At the moment we have about 300 Dell Optiplex 755s with Pentium Dual-Core E2160 CPUs. We are refurbishing them to run Windows 7 for our clients, but even with 6GB RAM they are still much slower than I would like.

    These CPUs handle overclocking very well, and the machine hardware is designed for faster, hotter CPUs. If the overclocking can be done, it shouldn't cause much trouble with heat or stability. The problem is that it is very difficult to overclock any Dell machine. I would like to make a customised BIOS which overclocks the CPU, and modifies other variables for the necessary stability.

    The machines are low value and we have a large number of them. If they can be successfully and stably overclocked, they will become vastly more useful and valuable for us and our clients. Since we have a large number of them, I can afford to brick a few attempting to do this, if it means that the rest can be significantly upgraded.

    What I've done so far

    I downloaded the latest BIOS update from Dell and applied it. Using Phoenix/Dell/EFI SLIC Mod v2.59 I've extracted the exe file and applied a SLIC file (had some trouble with the checksum but I think that was an older version of the program).

    So now I have a bunch of extracted files (the important ones I think are O755-A22.hdr and O755-A22_SLIC.hdr) which should be editable since the certificate has been applied.

    I think what I need to do is find the correct settings for overclocking in RW Everything, modify the file and apply it in the Phoenix Mod Tool.

    Where I'm confused

    1. Does RW Everything actually allow you to create extra menus in BIOS that are editable? So I could create a custom BIOS with customisable overclocking options? Or does modifying a BIOS this way just apply a permanent change? The documentation on RW Everything seems a bit sparse, or it might just be over my head.

    2. I still need to figure out what the overclocking settings should be. If RW Everything creates editable menus then I can just include the extra options and test from there. If it doesn't create editable menus then I will use software overclocking and stress-test the machines for several days to figure out what to use.

    3. Can someone give me some guidance on what files/parts of the .rw file I need to edit once I have the appropriate settings?

    4. Now that I've unpacked the exe, do I need to modify the .hdr file in Phoenix Mod, or has the actual exe file itself been modified, and should I continue to put that in the "Original BIOS" field.

    5. If the exe file itself is not being modified, how do I repack the components back into an exe file when I eventually flash the BIOS?

    I think that's it at the moment, sorry if it's a bit long-winded, and thank you very much in advance for any help you can give me. This is something I've never looked at before in my life, and it's much more complex than I had anticipated.

    Assuming all goes well and I can make a custom BIOS with overclocking for these machines, I plan to make a How-To for our website that I'll also post here, with all the relevant custom files. There's loads of these machines around (in London at least) that are currently being discarded, so it would be cool to save a few more from landfill and keep them useful a while longer.

    Thanks again.
  2. Tito

    Tito Super Mod / Adviser
    Staff Member

    Nov 30, 2009
    Directly using Phoenix Tool only gives you the opportunity to add SLIC. You have to unlock the locked tabs (if available) by manually patching the locks within different modules but it requires the idea of reveres-engineering.

    You need to use Dell Client Configuration Utility to repack the modded bios.

    RW report has nothing to do with menu unlocking.
  3. MarkConstantine

    MarkConstantine MDL Novice

    Apr 7, 2015
    Thanks for that Tito, that makes sense.

    I was under the impression that inaccessible BIOS settings (eg. in my case Base Clock, CPU multiplier, CPU Vcore) could be tweaked by creating a modified rw file in RW-Everything and applying it with the Phoenix Tool. Is that correct?

    If so, does anyone have an idea which bits I need to start tweaking and/or where I could find useful guides on it?

    I have tried googling a lot, but what I've found seems somewhat unclear and I want to be sure I'm understanding the process correctly before I start making tweaks.

    Many thanks again.
  4. MarkConstantine

    MarkConstantine MDL Novice

    Apr 7, 2015
    Just to say as well, I realised you needed a Dropbox account to access the rw file, so I've uploaded it to mediafire instead.
  5. Galileo Figaro

    Galileo Figaro MDL Junior Member

    Sep 6, 2010
    I have the same machine as you, and in a similar setting. It was donated to our computer club by some company. However, I'm not in London but in Sweden.

    I believe that what you're trying to do is a waste of time.
    If your machines are going to a charity then it's doubtable someone will complain about them being slow.

    My "real" machine died some time ago and this Optiplex thing has become my main computer until I find something new.

    I can tell you what my experience with the Optiplex 755 is.

    Patched the BIOS with SLIC 2.2. That's somewhat beyond 2.1, which is for W7. The 2.2 was for some MS server version. I don't intend to run any server software but patched the 2.2 version for fun. The normal SLIC is 2.0 for Vista. It also says something about Vista Ready on a sticker on the chassis. My problem with Vista is that I don't like it.

    Tried W7, XP, Mac OSX and finally W8.1 which I'm running now and which I like, with Startisback that makes it look more like W7.

    My Optiplex 755 has an additional ATI Radeon HD 2400 XT with a Y-adapter, so it can use two monitors. Without that card Mac OSX can't be run.

    Windows XP is a bitch to install on this machine. You need to patch your installation media with drivers for the SATA interface and also for the chipset of the motherboard in order to even make it run. Also, XP is in no way faster than W7 or W8.1, so it's pointless as well.

    You are right in that the machine is a bit old and slow. The cure for that might be more RAM, a USB stick used as speedup via ReadyBoost (eBoostr for XP) or via software that manipulates the clock multiplier (google for it). Going into BIOS for that is overkill. There's also a difference in speed for different HDDs and SDDs.

    Dell BIOSes aren't easy to work with. Maybe you should check out Coreboot? If you fail you can still reprogram the BIOS to its ordinary version with an external programmer. There are pads on the motherboard for that.
  6. sebus

    sebus MDL Guru

    Jul 23, 2008
    755 is a waste of time, it is what it is & you not going to make it any more in any way