1600 FSB mod (BSEL)

[Antinomy]

:welcome:
I've seen an active duscussion of the 1333 BSEL mod and decided to post here the info for all such mods and 1600 too.
So take a look at the picture
http://images.people.overclockers.ru/113487.png

We see all FSB that can be achieved by a BSEL mod.
Many people have tested BSEL 266 (in the times of Pentium 5XX and 6XX). Some tested BSEL 333 (FSB1333).
But I haven't seen any result of trying a BSEL 400 mod.

So, here are the recommendations.
We go to the theme about FSB 1333 mod (http://www.xtremesystems.org/forums/showthread.php?t=132900) and look at the Land listing. There are two red dots and one between them. To make a 333 mod you have to connect them. For the 400 mod you have to connect these two pins and the one between them. I.e. connect them together, all three of them.
I don't have such hard for testing the mod, but though it's only a case of BSEL mod, which works, it must work, if the CPU can work on 1600FSB and the MoBo can set this frequency.

Waiting for results.

[ziddey]

not until bios has provisions for bsel for 400

[JWilson]

http://www.lejabeach.com/pics3/dfip965s042607-1.jpg

[ziddey]

those were hidden, but do not work. p965 does not have either 333 nor 400. however, dfi board can take 333 bsel cpu's, since it has microcode programming to understand, but it runs at 266 strap. 333 strap would have dividers to allow operation in ddr2-800.

[Antinomy]

The 333FSB doesn't require microcode update as the stepping (and CPUID too) doesn't change. This operation can be done without support of the MoBo because the frequency is being set only by the clock generator, not the chipset. But the strap may not be changed if the chipset doesn't support it. Also, the BIOS can block this frequency, but it's not an ordinary case.
So I think it's worth a try.
How did you check the active strap? By the mem latency or smth else?

[ziddey]

yes, mem latency and the fact that there is no documented 333 strap with p965, judging by the ram dividers available (each strap will have associated dividers)

that said, production 333fsb will be out soon and looks to be g0 stepping. that said, i agree about clockgen determining bsel instead of ucode, although it still is in requirement of bios update to support such, which is why 400 bsel is unlikely.

[Antinomy]

there is no documented 333 strap with p965, judging by the ram dividers available (each strap will have associated dividers)
Agree.
although it still is in requirement of bios update to support such, which is why 400 bsel is unlikely.Only if the BIOS is too intelligent. Such as Asus & Gigabyte. But interesting to try on others.

[ziddey]

well intelligent in the sense that when you manipulate bsel, it won't work properly. but all in all, since bsel is read by the motherboard, the motherboard must have provisions for 400 bsel, which to our understanding doesn't

that said, it is worth a shot if you have a board that is known to take bsel manipulations. however, the odds are most likely against you

[Antinomy]

Yes, but for non-intelligent boards, that don't check the bus clock by comparing to the ucode the BSEL mod is likely to work. The reason was shown already - BSEL connects the FS pins on the clock generator, and the geneator can set a frequency of 400.

The only question is how will the MCH behave on an unusual strap, cause it'll change too. That's the only problem as I see.

[ineedaname]

er don't forget u'll need a cpu that CAN run at 400mhz without extra volts.

I posted how to do the 400 mod in the 1333 forum a while back.

[ziddey]

or at least to post 400fsb and be able to manipulate bios stably.

[Antinomy]

ineedaname so did work after all? Or nobody tested this? I found out this thing quite long ago, but posted it here only by now. I thought that here someone could test this. But was wrong.
Yes, this kind of processor is required. But for 6300 it's nothing.

[wwwww]

On DFI Infinity 975X, setting 400FSB via BSEL causes CPU to boot at 100MHz FSB (tested on E6300 - enjoy my 700MHz chip :P). Tested this ages ago, the board didn't even have bios support for the 333Mhz FSB.

[ineedaname]

I somehow doubt that many (if any at all) boards can do the 1600FSB mod simply because they weren't designed specifically for 1600fsb yet.

[Norway]

What a old thread :)

I'll do the mod on my QX9650 when i get time to do so, right now I also are stucked with a Gigabyte G33M-DS2R :(

[zoob]

BSEL mod doesn't work on Gigabyte boards (I've tested on P35-DS3R)

[bl1zZ]

Same here with my Gigabyte P35C-DS3R

[cky_munkee]

1600FSB BSEL mod did not work on my EP35-DS3P with BIOS F3 (supports Yorkfield QX9770 1600FSB)

[Chosen.]

BSEL mods don't work on Gigabyte motherboards.