Uncreative Labs

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I have been trying to get one of these things for a while. I finally managed to find one in China. Do any of you guys have one of these? I have heard some rather mixed feelings about this chips. Some people say they work great, and others say performance is no better than a 33MHz chip. I guess it has a lot to do with L1 cache.

I wonder how these compare with 40MHz DLC and TI 486SXL

Joined: 01 Oct 2004 Posts: 169 Location: behind you!

I had an ast advantage adventure 6066d and it had a cyrix dx2 66mhz and it rocked. Played doom2 full screen high res no problem. I have no hard numbers but feel it's on par with the intel dx2 66.

---edit---

BTW
It had on-board video that I'd guess was a local bus video card as even my best isa card gave nearly 1/2 the framerate in doom.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I think there is some confusion. Maybe I didn't make it clear enough, but I should have done a better job because these two Cyrix chips are often confused. I am actually not talking about the DX/2 chips with 486 pinout, but rather a clock doubled 386 upgrade part. It is called DRx2, and was not very popular, because it was released in 1994 when the Pentiums started coming around. It is similar to the Cyrix 486DLC chip, but is meant as a direct CPU replacement, so in theory you can use it on 386 boards that don't have DLC support. The DLC chips had a lot of problems because of the software related to the 1kb of WB L1 cache. The DRx2 chips supposedly eliminated most of the issues, and it is rumored that you can use the L1 cache without software. But, I am really not sure if that is true since I don't know anyone who has one. As far as I know "DR" stands for "Direct Replacement".

Another interesting chip is the TI 486SXL and 486SXL2. These chips were based on the cyrix core, but with 8kb cache instead of 1kb. They are available in both 386 and 486 pinout, but the 486 pinout is more common. Supposedly this is the fastest CPU you can get for a 386 motherboard, and performance is supposed to be almost equal to a real 486.

Two other good options are IBM 486SLC and 486DLC because they have 16kb L1 cache, but they were only available as surface mount chips. It is possible to find upgrade kits with some extra circuitry to use on standard 386 boards, but they are not common. In theory an SLC3 or DLC3 99Mhz 486 can beat the TI SXL2-66, but I have never seen a 99MHz model...just 60Mhz and 75MHz versions.

Perhaps you already know all of this, but anyway I am interested in personal experience with this kind of CPU...mostly concerning operation of the on-die cache. I believe that all of these CPUs are infact modified 386 cores rather than true 486s.

Joined: 19 Apr 2006 Posts: 261 Location: WisConSin

I owned a 25mhz 386slc (cough VERY similar to a 486slc) IBM Eduquest machine and the performance was MUCH better than a standard 386sx, it sat right around where I would expect a 386dx with VLB system to perform, it loaded up quickly even in windows 95 and depending on what you were doing could almost do as well as a 486sx-25mhz (actually it did better than several PB 486sx-25's I've had pass through my hands)
, also I noted that many 486 only programs would run on the beasty.

I also owned an ISA AT IBM Blue Lightning 486SLC-2 66mhz system board. For the brief period I had it in a case it performed very similar to what I got out of the multitude of 486SX-2 50mhz machines I had owned. The trick is it performs the same as another 486 ISA system, the ISA bus is the holdup on these machines but it was also a holdup on many older 486 boards anyway. Comparing a VLB unit to and ISA system board especially when it comes to video is many times pointless.

Many times these boards came with more L2 cache than their true 486 counterpart and could do better assuming of coarse you were using ISA components.

As far as I know the blue lightning and even the 386slc which are all MODIFIED 386 cpus that did have 486 code embedded in them making them very similar to 486sx chips.

They are not really clones of 486 chips, rather they are upgraded and completely independant enhanced 386 chips.

Joined: 19 Oct 2004 Posts: 138 Location: Lynnwood,WA

I had one of those in my old Duracom Laptop computer before I put an Intel 66 Mhz CPU in there. For some reason, the Cyrix did well with Windows 95 installed, but I wanted to use 3.1 at the time on that particular laptop, and 3.1 had some issues with it. It eventually got a second life in a GTSI 433DX/D (which is essentially a re-badged IBM PS/Valuepoint).

Joined: 01 Oct 2004 Posts: 169 Location: behind you!

I'll have to check tonight but I think I have 2 systems with that chip. One a ps/2 50 386 and the other a compaq portable 386. Both are seen as a 486 DX with most software.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Ryan, I think you are confusing 486SLC with Blue Lightning. The blue lightning chips are actually 32-bit DLCs. Though, the SLC2s also perform pretty well. A friend of mine had a 50MHz SLC2 system back when I was running a 33Mhz Intel 486. Performance was pretty much equal, except in floating point performance (with an 80387SX) which was much lower. The real Blue Lightnings (aka IBM DLC) are pretty nice chips. Maybe faster than the flagship intel chips at the time, but because of a licensing argreement IBM was only able to produce surface mount variety. I have never seen an IBM DLC in the flesh, though I really want one. It's pretty much the ultimate upgrade for a 386 system, especially if you can find the ones that use the 33MHz bus.
I haven't used a 386SLC before, but my understanding is that it is identical to the 486SLC except for a smaller 8kb L1 cache, so naturally I would assume that they are pretty fast. A standard 386SX system performs like crap, even when running at 40MHz. It's not much more than a glorified 286. Comparing an SX to an SLC isn't really a fair comparision.

Joined: 19 Apr 2006 Posts: 261 Location: WisConSin

The motherboard was DEFINATELY not a 386dx board, the cpu was surface mounted and identical to a 386sx in appearance, size and pin count (furthermore said IBM 486-SLC2-66mhz when it booted). The board could only hold up to 16mb of 30pin simms banked in pairs and had only ISA slots. The CPU was definately a IBM 486slc2-66mhz, the board however was labeled IBM Blue Lightning with a nice pretty blue holo sticker and blue silk screening.

More than likely some chinese hack. We all know how well they label things, like black plastic plugs that say write back on them.

Looking around, this place

http://www.cpupages.com/store/index.php?category=407&ctg_name=486BLDX2&PHPSESSID=24a0cc113f7c501510cece0c80c9b8bc

says that a Blue LIghtning Was for 486 Socket 1,2,3 totally different.

I do still own a TI 486DLC cpu and motherboard, it is socketed but probably nothing like an IBM/Cyrix chip.

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

Yes, it can get a bit confusing. I didn't mean that you don't have an SLC2 cpu, but rather that the SLC2 is not a blue lightning. I find it strange that there is a sticker on the board that says that. Perhaps it's really a DLC2 that had some of its address lines cut. Have you seen the writing on the physical CPU?

It's unlikely that you have a Chinese motherboard. As far as I know IBM was the only company that produced SLC2 and DLC2 motherboards. Though, perhaps they did outsource to somebody else. And, maybe you haven't seen one before, but there actually are surface mount 386DX chips, but I don't believe Intel made any. They look the same as SX chips except they are slightly larger.

Lastly, yes there are actually two blue lightnings. IBM originally had the contract with intel to modify and produce their chips, and they produced DLC2s and DLC3s under the "Blue Lightning" label. But, later they switched to Cyrix and decided to keep the Blue Lightning name because it sounds catchy I guess. Basically it's just a Cyrix DX/2 chip. The real Blue Lightnings (intel core) perform much better.