[ KB ] Original Dual PIII Notes

[Derek]

Category: 1 BP6 Specific
Type: Info

Article Name: Original Dual PIII Notes
Author: Derek
Description: First notes for Pentium 3s on the BP6.

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[tjcarst]

Were the Spectra III 850 successful?

[Derek]

[kuun]

whats a spectra III 850?

[hyperspace]

[phaedrus]

Hey all. I'm new around here. I just did the PIII mod using Neo S370s, following Yoichiro's guide. I've got a version 1.0 BP6. I cut the trace on the S370s and added the wire from AN15 to N33. The dual proc works fine.

I tested her with just this mod and the board was stable to a maximum of 83MHz FSB.

I then changed out EC10 for a 1500MFD cap (the previous owner modified the board using the $2 VTT fix, so my Q6 is a LM317T soldered right onto the old regulator), and the board is stable at 100MHz FSB, so I'm underclocking (yes, it rankles, I'm not much for overclocking---I like stability---but underclocking makes me feel gipped ) my 866MHz PIIIs to 650MHz right now. This seems to be the maximum I can boot at.

Something funny happens when I try 110, 124 or 133 (the ultimate goal). The board powers up, the kbd leds flash, the CD checks for media, and I get a whole lot of nothing on my monitor, it's just blank, nothing is displaying.

The rest of my hardware setup looks like this:

BP6 RV BIOS w/o HPT366 (I don't use them)

384MB PC133 SDRAM (256+128)

Western Digital 20GB drive
iOmega ZIP 100 (IDE)
LG DVDROM

NE2k PCI ethernet

SB PCI128 soundcard

GeForce4 Ti4200 -or- 3dfx Voodoo3 2000

Slackware Linux v10.0, Kernel v2.6.7

I get the same problem with both video cards, ie, neither display anything above 100MHz FSB. I downloaded and installed the RV BIOS to get the PIII microcode and hoping that the problem would clear up with the new BIOS (admittedly, a long shot, and I realized this at the time), the RU BIOS worked for booting to 650/100MHz.

Anyone have any idea why 110, 124 and 133MHz FSB would cause nothing to display? I've been thinking about trying to rip into BP6FSB and port it to Linux, to see if I can boost my clock on the fly, but I don't have time for that today.

Thanks all, this site is awesome, I wouldn't have gotten as far as I have without you guys. My system already feels much faster (but I still only get a maximum of 20fps in tenebrae and 3fps in hard to render areas... It's unplayable... (looks like they're trying to multithread it, maybe it's time to help them out a little... ).

Jeff

[hyperspace]

Welcome to BP6.Com, phaedrus !

Dual PIII's and Linux! Nice work! Not sure if you have read all of Yoichiro's modifications he did. From what I have read on his site, even if you do all the modifications, you still may not be able to get 110 or higher.

When you are running at 100 or 83, are you experiencing any random lockups or reboots?

[phaedrus]

[phaedrus]

Hey guys. I had a thought. I'm an electronics technician in a physics lab at the UW (this is why I got the mod going in a weekend, experience and access to the right tools).

Anyway, I keep worrying about the wires on the back of the sockets for the Neo 370S mod--solder is bad for making mechanical connections, and while the wire is light, and I'm not hauling my box around, I'd be worried about going to a LAN party with it.

So, my idea is this: glue the wires down with some kind of epoxy. I haven't tried it yet, but I think even just a 5 minute epoxy would make a very solid mechanical connection with the board, and shouldn't damage the PCB. Any thoughts?

Jeff

[hyperspace]

Sounds like a plan.

[purrkur]

[Billl]

I work in what used to be a card manufacturing shop. Now all we do is customer returns, but I do know a thing or two about card manufacturing. All we ever used was either two part epoxy or RTV to hold things in place. So you should be just fine. I'm not sure if I got his meaning about the attaching the wires though? If it were me I would solder them and then epoxy them to stop any movement at some nearby convient spot.

just my .02


Billl

[phaedrus]

This is linked to in the article, but here is a good picture of what I'm talking about. To get the PIII Neo mod going, you have to add the wires in the picture, and there's no good place to make a mechanical connection.

Most of the work I do in the lab is point to point turret construction. We do lots of radio frequency and cryogenic work, so sturdy construction with considerations of crosstalk and shielding is usually the name of the game. Since we do tons of custom designed equipment and only have 5 people working in the lab itself, quick and easily done by hand is also the name of the game. Turrets on PCB usually ends up being the best construction technique for us.

So, I'm not as familiar with etched PCB construction techniques, but I do know solder is a bad mechanical connection, and that we often use 2 part epoxy to glue DIP sockets and certain capacitors to the back of single sided PCB. I just did this on a board I built the other day, which is what made me think of using the epoxy to make a solid, insulated mechanical connection. I would just be glueing them down to the back of the board, it being the only nearby, convenient spot.

Billl, thanks for the confirmation on it working fine on etched PCB parts. I felt a lot better trying this knowing it's common repair practice (I don't want to screw up my BP6, it's my baby). I've been fretting over those wires--I've been avoiding moving my box just to minimize the chance that the wires would break. Anyway, I went ahead and did it, and it's working just fine--I'm typing this post on her. The epoxy is mostly cured, and over the next day or so, it'll finish curing. This should probably get added in as standard proceedure for those wires (they'll be much more reliable, and while we haven't really heard reports of the modded boards breaking, I wouldn't take a board without the wires glued down to a LAN party or the like).

I took the opportunity to take some pictures, I'll post them later (girlfriend owns the digital camera, and has her computer set up to grab the pictures. Girlfriend is now in bed).

Jeff

[purrkur]

Phaedrus: Could you please outline what mods you have already done on your BP6? My dual 650MHz machine is giving me problems but I haven't had time to look into it yet. Just wondering what you have done so far.

[phaedrus]

Sure thing. With pictures even! Check out my gallery, I've got pretty clear shots of all the mods I've done.

So far, I've done the Neo 370S mod (cut the trace on the adaptor, on wire on the mobo) and epoxied the wire down.

The previous owner put an LM317 in for Q6. To stabilize the board with the PIIIs in it, I changed out EC10 (was 2200MFD) for a Radio Shack Special 1500MFD cap (1000MFD + 470MFD 25V caps tied in in parallel). Without the RSS, I was stable at 83MHz FSB, and with it, I was stable at 100MHz FSB.

To date, that's all I've done. My other hardware is an SB PCI128 sound card, 384 MB of PC133 RAM, a GF4/Ti4200 (also worked fine with Voodoo3 2000), a Western Digital 20GB hdd, an iOmega Zip Drive, an LG DVD-ROM drive and a 400W PSU. Standard keyboard and an optical mouse plugged into the PS/2 port via an adaptor.

I'm planning on recapping the whole board and shorting diodes D1 and D2 (or whichever are suggested by the Neo guys).

I got to get to class. Later.

Jeff

[purrkur]

Hey thanks! Good pics there! Tell me, how was the LM317 job done? Did he remove the 1085?

I got myself an LM350A but I am sort of sceptical. The 350 can regulate a continuous 3 amp current but so can the 1085. My problem is that I don't know the 1085 that well and documentation on it is not easy to find.

[phaedrus]

The 1085 is still there. I, personally, would have removed it (now that I think of it, LM317's are cheap, I might just redo the job). My Vtt voltage still fluctuates +/-10%, but it hasn't been affecting stability. I don't know that I've ever been able to find documentation on it [the 1085].

I went by Yoichiro's table for EC10 based on the Q6 regulator used (which I'm sure you've seen).

I've seen at least 3 different suggestions for what to do when re-capping your board. Yoichiro has his suggestions (under further mods), Friendtech has an update on the Neo 370s mod where they suggest cap value changes (as well as shorting a couple diodes and changing some resistor values) and finally, the www.motherboardrepair.com guy [Gary Headlee, who's been getting quite a bit of flack on these forums of late] recommends moving every cap above 1000MFD to 1200MFD (I emailed him to ask about this and got no responce, go figure).

I'm still trying to figure out which way to go. I'm going to replace all my caps, but I don't know which of those three suggestions to go with. I'm actually leaning toward the 1200MFD all around solution with EC10 kept at 1500MFD, and then if that doesn't get me to 133, I'm thinking about trying to short the diodes as per the Friendtech mod, and see what happens from there.

Jeff

[purrkur]

I can't say that I have seen the extreme Vtt fluctuation on either of my boards (ver 1.0 and 1.1) which is why I am also sceptical on replacing the Q6. I have also seen all of the mods sites that you mentioned and there is one thing that bothers me about the Friendtech's recommendations is that they don't mention why these changes should be implemented.

I can mention that the caps that I replaced were all of bigger size (in terms of microF and physical size) than the originals but I used the same voltage specifications. I replaced the 8 caps around the voltage regulators and the 12 caps around the ZIF sockets.

I am not so sure you will ever see 133 on the BP6 no matter how much you try. I think the adventurous over on this forum have reached 110 but thats it. I makes me wonder how the NEO 370S handles overclocked frequency as opposed to the frequency switches on the adapter itself?

[phaedrus]

[purrkur]

[phaedrus]

I've had similar problems. What video card are you using? I've found that the 3dfx drivers are unstable (and unmaintained, so it's not likely to get fixed any time soon) as well as the closed source nVidia drivers. I've setup my system so I can run with the opensource nv driver when I don't need the 3d acceleration. That cleared up my problems.

Jeff

[purrkur]