Another system update! I wasn't happy with a couple things in this build, and my new hotness CPU came in, so it was time to pull it out and make some changes.

I needed to do a small hardware mod to the board, so out it came:

Marked off the appropriate pins:

...and got out the soldering iron.

I'm not bad at soldering, but I have to admit, taking the iron to my best & only Super 7 board, which I've had since new, was legit terrifying. Fortunately it worked out.

Does it POST? Sure does!

Incidentally, before I did the resistor mod, I benchmarked a bunch of other CPUs (including Intel and Cyrix) in order to get baseline results. So eventually I'll be able to answer whether this affects those, positively or negatively, or whether it only makes a difference on afflicted K6es.

Because of where this machine lives, I really wanted front USB ports. There actually is a USB header on the board, but it's whatever ancient 1.0/1.1 standard that existed back when this board was made, and I don't trust the ALI chipset to have it implimented very well. I had a PCI USB2 card in there already, but it didn't have an internal header. So I found this other one in my stash (actually installed in my PowerMac G4) with the same NEC chipset that I've had good luck with:

It has an internal USB port (I don't know why so many cards have this? I really haven't found anything that would use it!), but also a single row of pins to attach a header to. Incidentally, I tested the header pins against the port itself and found them to be directly connected - in other words, these are the "same" port and you can't use them both simultaneously.

With that determined, let's get that "external"-type port de-soldered:

I'm pretty proud of this desoldering job, TBH. I just have solder wick and one of those hand-operated vacuum pumps, nothing fancy. Since it came off so nicely, I can re-use this USB port in another project if I ever need one.

With the internal port gone, I can use a 90° pinheader, which makes using it heaps easier when it's installed in a machine:

Unfortunately there's only one row of pins, which means this supports one USB port. I've found other cards with a proper 2-row header (and done the same mod on them), but this is what I had on hand.

So, with that in mind, I spent way too long bodging this front-bay port up:

...before deciding I didn't like it. It didn't fit all that well (this is a random front panel from some other long-gone case), the cable was too short, and the ground I added was causing problems (I think?? long story.) This didn't make it into the final assembly.

Because all the PCI slots are in use, I had no room to add a fan onto the Voodoo3. It's like a board sandwich in there:

I've never had a problem with the stock passive heat sink, but the V3 does get hot, and for piece of mind more than anything else, I really wanted to run some more air over it. So I came up with what I think is a pretty neat little solution.

^^ I scavenged this 12V fan out of an old 1U server ages ago. It's pretty deep and pushes a lot of air for its size, probably more than necessary, but it'll do. There was actually a 3rd wire for PWM speed on it, but I don't have any way to control that easily (or monitor the V3's temperature for that matter), so I took it off and swapped the connector for a simple MOLEX one.

I added this bracket (a rack ear for something or other) from my parts bin onto the back:

...and bolted it into place:

Aside from the connection to the back of the case, it "floats" where it is. I might try to add some sort of hinge so I can just pull it out of the way when I need to swap cards around. It pushes a ton of air over both the Voodoo3 and the PowerVR (and even the sound card, but I don't think that gets warm at all) and brought "finger temps" down noticeably.

It was kind of luck (there's a bit of adjustability in the bracket), but it lined up really well with the V3's heat sink:

(Ignore the "AIR FLO" direction arrow, I turned the actual fan around so it pushes air towards the GPU. It made more sense to me that way...)

There's still a good 3-4cm between this fan and the case side panel, so there's plenty of room for it to draw air from when everything is closed up. Being a high-RPM server fan, it does make a bit of a whine, but you don't notice it so much with the case closed and the system under the table. (I tried wiring it up to 5V instead but it was too weak.) Overall, I'm pretty happy with how this turned out.

So let's see that new hotness CPU (yes, it was already in there at this point, I'm posting this out of order, but whatevs.)

I'd actually pulled it out to do the thermal paste (again!) I'd been swapping chips around to benchmark them so I cleaned everything off before re-applying:

There it is, arguably* the fastest thing you can put on Socket 7, a pristine-looking K6-2+/550ACZ I got off the big auction site for the princely sum of $20 USD. I've never messed with one of these before, so I didn't know how much of a bump over my non-+ 500 it would be going in.

(* maybe a K6-III or III+ at the same clock speed would be faster, but they're clocked lower 'officially', and I don't think the difference between a 128k & 256k L2 would account for that much. Also, the uber-rare K6-2+/570 runs at a lower FSB (95MHz) which might negate the 20MHz clock speed boost. Like I said, arguably.)

BTW I still love this blue heat sink. The fan is pretty piddly, but it's the same fan I've always used with this setup and it seems to be more than enough for these cool-running chips.

All cleaned off on the bottom:

Incidentally, I wasn't running it like this anymore, but here's what it looked like when I FIRST (re-)built this machine last year:

Yep, the original UPC sticker still attached and someone (me???) had just thermal pasted right over that. WTF. Interesting that I seem to have gotten this at a local auto parts + random surplus chain back in the day. I don't remember sourcing any of this stuff originally TBH, but my family had a local "computer guy" dealer who we used to buy a lot of stuff from back in the '90s.

While I was at it, I pulled the heat sink off the Voodoo3. It was originally attached with this thermal sticky pad. I cleaned it off as much as I could and gave it a nice, even surface spread of Arctic Silver 5, same as the CPU. I hope that was the right thing to do...

I also ende up doing a PSU swap. Something happened that made me just a tiny bit suspicious of the old one (it tripped the breaker on my surge protector while running, MAYBE to-do with that poorly-implemented ground wire on my USB adapter from earlier.) It still seemed to work fine, but I have tons of spare PSUs, so why take the risk?

After rummaging around in my stash, I came up with this Enermax EG465P-VE. (The AOpen is the one I was using previously.) It's not really any newer, but I knew it was in good working order and had previously been powering my 478 P4/3.0HT+HD3850 rig.

Both of these are complete overkill for this setup, but the Enermax gives me a detached 20-pin connector, lots of MOLEX connectors, dual 3.5" floppy plugs, and even a -5V rail. It also has a bottom-mounted fan instead of front one. It'll do nicely.

Unfortunately it also came with a LOT more cabling I'd need to stuff inside the case:

BTW I opened it up to have a look at the caps or for any obvious signs of wear, but nope, pristine inside:

(The voltages reported by the BIOS with this one are bang on and rock solid BTW.)

So with that installed, some more cable management was in order. For some inane reason, ASUS's engineers put all the IDE / FDD connectors on the BACK edge of the board, next to the keyboard connector. This means especially in a "deep" case like this one, you have ribbon cables stretching across the entire thing and blocking access as well as looking ugly. I always hated that.

Before:

Once again, I dove into my stash of parts and found some round IDE cables and even a rounded single-position FDD cable that was long enough. I tied off the extra PSU cables with some twist ties and stuffed them above the DVD-ROM, and tried to keep everything "exposed" in the case to the bare minimum needed.

After:

Still not great, but better. The main (only) HDD is alone on the primary IDE channel so I could swap that for a single-position cable and clean it up even further, but I didn't find one and this is good enough for now.

If you're still here, thanks for reading so far! I'll get to the exciting part (benchmarks & overclocking 😉 ) in the next posts.

That's a great SS7 system you have. My dad had a friend of his back in the day build us a very similar system for the house hold I think we still have the parts some where. Very much looking forward to seeing your benchmark results