I honestly didn’t expect a reply since this thread was so old, but this is becoming a project PC and I just want to add in maybe a 7700/7700k. Mine (G20CB) has HDMI out so it can use on-board GPU.
The EDIT link to the modified BIOS, is that a stable UEFI to flash? Or is there anything I need to know before flashing it? If there’s no problems with it, thank you so much!!
EDIT: Does this BIOS also remove the 256GB M.2 limit?
Got mine used for 200$ last week and like you i went onboard started to see how much i can push this little box.
Just ordred a 6700K and 32 gigs of sodimm CL15, i think i’ll go with a RTX 4060 since the powerusage on those are abysmal.
Liquid metal+2 vent holes for the CPU though the side panel should keep this one pretty cooled.
I just mounted a 512 GB NVME m.2 on stock bios (works fine), will try a 2TB stick later this week 
Havent got the modded bios working:
Error 368: Failed to disable write protection for the BIOS space.
FPT Operation Failed.
I actually bought mine new wayyyyy back then. I saw it on a BestBuy endcap and I was like, yep, I’ll have one.
But yes, I dug mine out of the corner to run a NAS server and when I loaded Windows 10 and saw how fluid it runs (like REALLY good) then take into account it’s got a socketed CPU, SO-DIMM’s, a honest full x16 PCIe3.0 slot, and everything else, including an M.2 slot… I was like let’s crank this thing back up. But the case had to go. I’m making a custom wood case for it out of cedar with airflow tunnels and things. More like a conversation piece (because I removed all the lights and things and will integrate those in the case, I already bought a backlight diffuser and cut it up and placed it over the light strips to look better where they’re mounted). Then I got an XFX RX 6650xt and the little thing screams. I love it. I can max out most titles. I don’t play higher than 1080p anyway. Anything more is just a loss for me, plus more FPS @ 1080p.
But I’m pretty sure you’re gonna need an SPL flasher and another BIOS chip which you can get off eBay for like $12. It’s just a WINBOND chip. Get the SPL flasher, initialize and flash the new chip, pop the old one out for safe keeping, and plug the new one in. ← Another plus for this board. Removable/replaceable BIOS chip!
I’m reallllllllly interested in if the 2TB drive will work. I’ve been told this is limited to 256GB but I’ve seen other people try different types of drives and they work fine. I’m thinking to get to higher capacities it needs to be NVMe, not SATA (which was what a lot of people on the ASUS forums were trying and not working).
EDIT: I saw where someone is trying to modify this board for ReBAR too! …and it’s you. HAHA. I didn’t read up the thread.
Hah! sounds awesome!
-please provide some pictures 
Thanks for the hint about the bios chip, will go shopping on ebay straight away.
Black friday/cybermonday is right around the corner so would be silly for me purchasing GPU/nvme right now…
But going for a Evo 970/980 or crucial 2 TB (PCI 3.0)
Do you have a link for the rebar topic?
LOL, you posted it right up there… going all the way back to X99 and the 3rd gen. I’m looking through the current BIOS now and trying to find any strings or anything referring to this and seeing if it can be enabled on this specific model. I’m sure it would also help my RX 6650xt too.
Yea if you can get REBAR up and running would be great, would also make the ARC GPU’s (they are dirt cheap) a possibility.
Have you tried to boot the 7700K yet?
I am looking at it. The ReBAR mod is going to be a bit harder than the modifications for adding 7-series.
I have and with the SPL flasher attached to a R-PI, it will program the new chip, then you can just pop it in. The flash works fine for me, although I haven’t received my 7700 yet. I’m not going to use a K version as I can use the HDMI port on my board if need be, if something happens with the PCIe slot or mucks up HDCP/driver compatibility with modified BIOS versions or if I need to use the machine with onboard graphics for diagnostics or recovery.
Really excited if the flashing end to work out !
Have you tried the overclock linked to earlier?
-could be a great combo if both rebar mod and the overclockable bios could be merged.
I ordered a bios chip yesterday and got a Rpi 4 (but my coding skills are quite limited).
Do you have a direct link to the STL flasher you use ?
Also please provide some pictures your current setup
Ps. have you checked the Dell 330w mod out, some crazy dude even combined two of those https://rog-forum.asus.com/t5/rog-desktops/330-w-psu-for-gtx-970/td-p/564262
EDIT: wrong link… !
https://rog-forum.asus.com/t5/rog-desktops/780-watt-asus-g20aj-mod/td-p/615703
O_o
Nah, I haven’t seen a power shunt mod quite like that. I really wouldn’t attempt that because you could blow some board caps and VRM’s sky high. It’s only rated for so much from that plug… I use the HP 230W Delta PSU. BUT… that’s only for the board and the CPU/RAM/Ports. My GPU is connected to an external 700W modular PSU with a PSU-On/Off switch I got from Amazon. I turn the external PSU on then switch the PC on, that way nothing on the board is strained and everything runs cool. Since this is a bespoke board for this PC, it’s unique. I wanted to keep it from exploding. lol. 780w through some of those VRM’s will literally blow them off the board. So I don’t use any board power for my GPU. It’s all going to the low current/pull board parts.
I’ll try to take some rough pics and post them.
The amount of modding done to this little box AJ/CB/CI is pretty remarkable.
-New CPU (6700K) for the CB is getting delivered next week (including a delid tool and a copper IHS + Liquid metal).
-The possibilities if OC via bios / BCLK could be unlocked!
Just bought a Gigabyte 8GB RTX 4060 (incl. 25% VAT ) for 300 USD!
I know, double posting is a sin, but for the sake of the internet archives i’ll do it
Current setup
6700k+LM+Ventholes
NVME 2tb getting delivered on friday
EDIT: Works without any problems, booted straght to win11 installation (flashdrive).
2TB P3 M.2
Drive spotted by system straight away
HWinfo
Installed a small Noctua fan to cool the NVME.
That is amazing! I’m still building a case. lol. It’s got to be right.
Seeing the original casing on yours with the OG GPU cage thing is something. My CPU fan cage wasn’t black though. That’s interesting. I had the OG 1070 model. Could you post a disk speed test? I know it’s supposed to be a x4 3.0 PCIe slot, but I would love to see some speeds to see if that’s a true 32Gb/s slot. It also does USB, so if you wanted to use, for some reason, something else there, PCIe and USB busses are both connected, and I think SATA. You can put a SATA M.2 there as well.
Here you go
EDIT: Added CrystalDiskMark
Just read that BIOS with unlocked OC cant run without disabling Hyperthreading so its kinda useless…
BUT this gives another opportunity:
[GUIDE] Coffee Lake CPUs on Skylake and Kaby Lake motherboards
Sorry. I decided to jump in to this thread. I’m thinking putting CFL Mobile for G20CB. Anyone did it successfully for this particular mod?
I’m actually looking for the BIOS that is already unlocked for overclocking so i can do my testing and sharing in return for the BIOS for anyone to play with.
Thanks
Hello @reactive hope you can help. i have successfully made one but need to make sure if this is okay
Hi @MattGuyver,
It is a long time ago I made something for g20cb and g20ci.
My g20ci is still running on 9900k…
What do you need. I will try to remember.
What you need is a programmer. Read out your bios off the Mainboard 3 times or so and compare the image with the others to be shure you have a valid image.
Then modify it and flash it back. If everything works, you are done.
It is definitely an advantage to have another flash ic, so you can simply swap it back. Some Mainboards use identical ic which definitely fit
Hope I can help you
Hi @reactive, can you perhaps help me with some information? I am also using an i9-9900K on a G20CI but a strange stability issue occurs (I described it in this post). Which SODIMM modules are you using and is your CPU an SRELS (P0 stepping) or SRG19 (R0 stepping)?
Hi @vega,
My CPU is srg19 but I had this memory issues too with Kingston HyperX 2x 32GB DDR4 2666 CL16.
A Memory instability issue occurs because of the memory setting DDR4-2666 of the i9.
BIOS is set to auto, so 2666 is set. I thought this is a problem with the Mainboard. The memory traces on the board aren’t able to handle this. Has to do with special electronics requirements. Explaining this would take a while.
Simply set the memory to 2400 via coffeetime. If it doesn’t work 2133.
My G20ci is running on 2133 with win11 without issues.
Hello @reactive i appreciate the reply.
To start things off. My Goal for G20CB is to have the CPU Installed with a Mutant 1440 to LGA 1151 CPU QTJ0.
I was reading the posts here and the files are missing that the G20CB has been transplanted with G20CI BIOS for added functionality and i wanted to test since i have a programmer and i have spare chips to play with added Coffeelake patching to be done just in case.
Anyhow, i need to find a BIOS that was here on this thread that the G20CB can be overclocked or via BLCK Adjustment for me to increase it’s capabilities for that Specific CPU.
Just in case you are wondering why this CPU? It is quite expensive to get 9900K in my country as the secondhand market dictates and i’m putting an option to use CC150 for this G20CB as last resort if i cannot tame the BIOS for the CPU QTJ0’s maximized capability.
Likewise, do i need to use the REBAR for this also? I will be installing RX7600XT and hopefully it will just just fine.
Hope you can steer me to the right direction and i will be happy to share my thoughts too and files that are permanently shared to this forum.
Thanks
Hello @vega have you tried using SAMSUNG based RAMs? Those RAMs has many wonders even those OEM ones.
