PDA

View Full Version : Pin/Solder Mod a Pentium D 805 - help please?


CoolioCat
03-30-2006, 01:26 AM
Time for some serious pleading :worship: to the more talented members of XS here...

I've got some Pentium D 805's i'd like to pin-mod. :cool:

Since s775 makes that hard, i'd be happy to solder (or conductive paint) mod at least one of them to a fixed FSB speed. Instead of 533FSB as they are by default, let's say i wanted to put it to 800FSB.

That means, on 20x multi, it'll boot at 4GHZ when set at 800FSB (if i'm getting all this correct). It's a bit much for the cpu perhaps, so i could always set the voltage to be perhaps 1.45 or 1.50 via a solder mod too...

I recall a thread by Socrilles here Solder Modding... (http://www.xtremesystems.org/forums/showthread.php?t=69913) that showed a cpu raised from 800 to 1066, but that was by making BSEL0, BSEL1 and BSEL2 all low resistance.

I hope he doesn't mind, but i'll just rip three lines from him here:

FSB is determined by the settings of BSEL0, BSEL1 and BSEL2
(L = low resistance/grounded, H = high resistance)

for 533 fsb they are H L L
for 800 fsb they are L H L respectively
for 1066 fsb they are L L L so you have to ground BSEL1, therefore you can make a connection between BSEL1 and BSEL2 to ground BSEL1.

Now 1066 is too much to solder mod the 805 to (unless you have serious cooling), so i'd be aiming for 800 fsb.

That means:
1) set BSEL0 to L instead of H
2) Set BSEL1 to H instead of L

Is it possible for anyone to show me on a 775 socket diagram which pins are best to solder to which other ones to achieve part 2?

1) can be achieved by connecting BSEL0 to BSEL2 (nice and easy since they are side by side)

but i'm not sure about making BSEL1 be H

I'd need to increase the default voltage by soldering too I imagine, perhaps to 1.45V (by connecting VID4 and VID5 together?)

I'm happy to do the work, but i'm not yet confident enough in choosing the right pins to actually do it... hence the request for some advice and help... :D

(p.s. the motherboards i'd like to put these into feature NO OC abilities AT ALL, hence the request! However, i can test the cpus in Asus P5WD2 or something first to ensure they can reach the 800FSB)

The specsheet i'm going by can be found right here. (http://download.intel.com/design/Pentiumd/datashts/30750603.pdf) Sections 4-1 and 4-2.

I don't have a paint program installed on this machine, otherwise i'd have grabbed some pics of the pin layout and asked someone to simply draw some lines on the pic as to which pins to connect etc.

... Is any of the above even really possible?
Is this all complete :bs: ?
Perhaps :am:

CoolioCat
03-30-2006, 10:27 AM
I think i've figured out how to pull BSEL1 to high (H)... you insulate the pin. So either i cover the relevant pin (round dot) on the cpu with a piece of rubber (a scrap from some wire sleeve or something), or i wrap the pin on the motherboard in insulation...

Or more dramatic - i snap the pin out of the socket.

I think i'm getting to grips with this now :rolleyes:

CoolioCat
03-30-2006, 02:35 PM
Another thought looking at this stuff again tonight - perhaps i can pull BSEL1 from (L) to (H) by soldering between BSEL1 and one of the VCC pins. There is one right above/below (depending on your perspective) BSEL1

Ah screw it... Will give all this a go on Saturday :eek:

I'll keep all this lot here purely with the hope it benefits some other user out there interested or rather new to all this pinmodding stuff (like me).

viper650
03-30-2006, 02:56 PM
uh, why not just buy a board with overclocking options in the bios? am i missing something here?

CoolioCat
03-30-2006, 03:02 PM
Quick summary:

533 to 800FSB:
---------------

1) Link BSEL0 to BSEL2 (G30 and G29) to ground both pins

2) Link BSEL1 to VCC pin to raise (H) the currently (L) pin (connecting H30 and J30)


Volt Mod from 1.4V to 1.465:
----------------------------

1) Link pin VID1 to a VSS pin (AL5 to AK5)

2) Link pin VID5 to a VSS pin (AM4 to AL4)


Please someone tell me if they feel the above will NOT work... or in fact, if possible, assure me that it'll work a treat :)

CoolioCat
03-30-2006, 03:04 PM
viper650: The motherboards i'd like to put the 805's into feature NO overclocking ability what-so-ever in the bios and buying a replacement board is simply a no-go for these chassis; they were custom designed around (initially at least) a 9" x 7.5" case.

socrilles
03-31-2006, 09:19 AM
There is a little info on this over at hardforum if you dig up one of my old threads (search for Dell in the overclocking forum). To make a High, I think the guy had to isolate the pin, so I would suggest trying to do that, which must be pretty hard on the lga 775 socket. Also are you sure that these chips are going to be able to run at 4 ghz!??!!. I think there is a couple things to worry about if they are in a SFF, one is the amount of power it will take to run them at 4 ghz, and 2 the amount of heat they are likely to produce. Anyway GL with the OC.

CoolioCat
03-31-2006, 11:26 AM
Ah thanks very much for the info... Found the thread and it confirms what I suspected. i.e. isolating the pin is correct. Also good to read that the only thing that 'should' go wrong if this little test fails is a no-post.

The PSU's are capable, the CPU's are capable (but a volt mod may be necessary to prove reliability) and the cooling should not be an issue either.

I'll test each CPU in an Abit board before modding to ensure they can reach the required speed and what kinda voltage is required to do so.

Thanks!