ducegt

External BIOS programmer, but you should be able to use Flashback with the mod described in the thread.

I have also successfully flashed 2603 and have rebar working. ? dsanke

Asus released 2603 Beta Version -Add Resizable BAR support for Nvidia RTX 30 series cards to potentially deliver more performance to gamers in select titles. Hopefully Dsanke can port it soon!

I first flashed with flashback and somehow broke it. CH341a is a cheap BIOS programmer with a tool called flashrom that worked.

ROG-MAXIMUS-IX-APEX-ASUS-2301.7z

You only need the BIOS flashed to use a 7700K. And it's okay to leave the other BIOS original. I did this myself in the past.

One great feature missing from the Apex X BIOS that the IX has is CPU overclocking temperature control. This is very helpful with my 7700K and I imagine it would be even more beneficial for a 9900K or KS. I've modded a stock IX BIOS (version 1010) that only has the microcode for the R0 stepping of 9900K and should work for 9900KS if anyone is interested in experimenting; send me a PM.

New official Apex X BIOS released today. Safe to assume "Support Intel upcoming CPU" is the 9900KS.

Awesome! What CPU did you use?

Woah, the 4400 memory divider is working for you? Or is it reading it incorrectly? Maybe 4133 is the upper limit for Kaby Lake only...

The Apex X (which the modded M9A bios is ported from) has supported the 9900KF since 1801 so you should be good there. Several users reported no issues with memory overclocking and 9th gen chips as well. 4133 is the highest divider Z270 supports and being you can't push BCLK above ~103... You won't be able to push 5K, but can run ~4266 at very tight timings.

Thanks guys. I got it working. I think the recent Windows 10 update automatically turned on Hide Extensions for Known File Types. *laughs while crying* With the stock 1301 BIOS I could boot 4133 1T about every other boot, but 2003 won't ever post with 1T; with same voltages as before anyway. 4133 16-17-37 2T 1.445v is stable for 24/7.

Do both hardware mods need to be done to flash a modified BIOS via flashback? I tried pencil and a small screw driver to short the pins near the BIOS chip, and I may have had them soldered at one time, but flashback would not work. I didn't mod the other part of the board. I'm using a 7700k.

@davidm71_2 You are the wiser man. I bought the open box ("all sales are final") before I saw the promo code that you must have used. Let me summarize how I spent about 10 hours swapping boards, coolers, sticks, redoing liquid metal, etc.. There's a happy ending at least. Swapped a 2.5 year old working 5+ ghz 7700k from a Z270 K6 to the Apex and it wouldn't post if the memory slot closet to the CPU was filled. So, I figured the open box mobo was bad... Swapped back to K6 and the 2 closest slots to CPU had the same issue so I lost dual channel. I figured I damaged my delidded chip from over tightening or maybe the Apex ruined it. It's clocking profile has changed..before delidding I could do 8 hours stability test at 1.28; great chip. Now, 1.22v @ 4.8 almost hits 100C..I remounted the cooler and socket countless times. I though maybe single channel was stressing it extra. Today, I was considering returning the Apex being my rebate was already approved and I decided to look it over one last time. There was one pin in the socket that was off by maybe 20 degrees. It was almost touching another pin which made it very hard to see that something was off. Anyway, my 7700K is now working with both slots in the Apex! I got no idea what's wrong with the K6 and can't be bothered with it anymore. I've only spent a few hours with the apex, but it's looking stable at 4133 CL16-16-36 stable with 1.47v. 4266 wouldn't post for me, but it's not a real divider; it increases bclk. I'm wondering if we can use the higher memory dividers that the Apex X supports with the modified BIOS. I'll probably give it a shot now that you confirmed the modded BIOS works with SKL; thanks for sharing that.

Yes. $100 - $60 mir.