Dual Pentium III on i820


I have read the article about making a FC-PGA Pentium III work on a Celeron PGA370/Slot1 adapter (http://www6.tomshardware.com/cpu/20000229/index.html), and I figured that you won't mind if I bother you with a problem I have, that is sort of related to the article. Here goes the story:

I have a Fujitsu-Siemens B200 server, which has a Fujitsu-Siemens D1159 mainboard (dual Slot1, Intel 820 chipset, 128MB RDRAM). Initially, it had one Pentium III processor at 600MHz (Slot1 format, Coppermine, 256K L2 cache, 133MHz FSB). As I had at hand other 2 Pentium III processors at 667MHz (with the same 256K, 133MHz FSB...) I figured I could make a Dual system. The problem: these two are Socket370 format. I said "OK..." and bought two Socket370-Slot1 adapters. Surprise: they don't work! After a little digging on the Internet, I found out that the adapters I have are for the old PGA370 Celeron (this is when I found your article). I also found out about the differences between PGA370 and the Socket370 Pentium III format... Again I said "OK..." and got busy modifying the two adapters (as described in your article). The operation was partially successful, as follows:

1. The processors work fine, except that they work at 500MHz (100MHz FSB, not 133).
2. They don't work in Dual configuration. Separately (one by one) they work as described above.

My first priority is to make them work in dual mode. Secondly, if possible, to make them work with 133MHz FSB as they should. Please be kind and help me solve this problem.

Thank you very much!
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More about dual pentium i820
  1. Buy two NEW adapters, modifying the old ones has always been a bad idea. The Coppermine compatable adapters have been around so long, they are no longer a current product. That's what you should have bought. But they're getting hard to find.

    You can get two Upgradeware Slot-T adapters if you like. These are garunteed by Upgradeware to be dual CPU compatable, and support both Coppermine and Tualatin core processors. As such, you could use two PIII-S 1400's (512k cache) if you liked, or the two PIII's you already have.

    <font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
    <font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>
  2. insulate pin a14 (for 133mhz fsb) on the sc242 socket, you can use tape or nailpolish really anything

    If it isn't a P6 then it isn't a procesor
    110% BX fanboy<P ID="edit"><FONT SIZE=-1><EM>Edited by piii_Man on 12/08/03 09:50 PM.</EM></FONT></P>
  3. Thank you for your help.

    Crashman: I know it is not a good idea to modify the adapters, but I had no choice. I could't get a Coppermine ready adapter, even these two were quite hard to find.

    piii_Man: Could you please provide me an electronic schematic of an adapter or better tell me how to locate the A14 pin or where is it exactly. The modifications I made were done by looking at pictures... :(
  4. Here is a link to a web page provider that still sells the adapters. $18.32 is a great price.


    Barton 3200+ 400MHz
    A7N8X Deluxe
    2x512 KinstonHyperX PC3200
    GeForce FX5900
    Maxtor DiamondMaxPlus9@80Gig
    SONY CD 52x
    SONY RW 52x/24x/52x
    SONY DVD 16x/40x
  5. piii_Man: Isolating pin A14 worked like a charm! I used some tape. Thank you very much! Now all I need to know is how to get them work in dual mode. How do I do that?

    <P ID="edit"><FONT SIZE=-1><EM>Edited by Slider on 12/09/03 10:53 AM.</EM></FONT></P>
  6. my guess is to enable smp you must do <A HREF="http://www.ocworkbench.com/hardware/overclock/celeron/dual.htm" target="_new">this</A>

    This is all at your own risk and i do not take any responsibility for any damage you do. I am not even sure if this is your problem, but if you are too cheep to buy some smp adapters this may be your problem since you are using a ppga celeron adapter.

    If it isn't a P6 then it isn't a procesor
    110% BX fanboy
  7. After some thought i think that the mod above should solve your problems...probably since you are using a ppga celeron adapter they have flat out disabled that pin. Anyhow go to page 68 of the preceding spec sheet to see the pin side (processor facing up on your desk, or slocket adapter w/ the mounting side down).

    <A HREF="http://ftp://download.intel.com/design/PentiumIII/datashts/24526408.pdf" target="_new">piii fcpga data sheet</A>

    If it isn't a P6 then it isn't a procesor
    110% BX fanboy
  8. I already did what the guys from Kikumaru said in the article. There's a strange thing here: AN15 and B75 were indeed not connected on the adapter. BEFORE I connected them, when I plugged in the two processors, the system did not recognize the second processor and didn't boot either. AFTER I connected AN15 and B75, the system won't even start with both processors plugged in. It only starts with one processor. I guess here must be something else that needs to be connected.

    It is not about being cheap, but I'm not doing all this for me. And it is hard to convince the faculty to give me money to buy something... Besides I really want to do it this way. Call me a maniac if you want... :D

    <P ID="edit"><FONT SIZE=-1><EM>Edited by Slider on 12/10/03 05:28 AM.</EM></FONT></P>
  9. well if you have nothing to do with those processors be sure to send 'em my way :smile: .

    Really you are using adapters never ment for smp in an smp board, you are bound to run into problems thats all i have to say.

    If it isn't a P6 then it isn't a procesor
    110% BX fanboy
  10. It is not about adapters MENT for dual, it's about a wire that is not connected.
    Would you believe me if I told you that it finally worked? :)
    After a little digging inside the specs from Intel, I connected pin N33 to B75 (obviously AFTER I disconnected the AN15 from B75). Of course, I take no responsability if any of you do the same thing as me and damage your stuff... ;)
    Too bad I can't post a screenshot... :(
    Thanks a lot for the FSB 133 tip!
  11. Odd, good luck with the new cpus...

    If it isn't a P6 then it isn't a procesor
    110% BX fanboy
  12. Here are some benchmark results with Sandra:

    CPU Arithmetic Benchmark:
    - Dhrystone ALU: 3567 MIPS;
    - Whetstone FPU: 1767 MFLOPS

    CPU Multimedia Benchmark:
    - Integer iSSE: 11571 it/s
    - Float iSSE: 13743 it/s

    Memory Bandwidth Benchmark:
    - RAM Bandwidth Int Buffered iSSE: 753MB/s
    - RAM Bandwidth Float Buffered iSSE: 749MB/s
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