I've got an older machine with a Socket 7 motherboard and a Pentium 166 MMX chip and want to upgrade without swapping in a new motherboard. So I'm limited to Socket 7 CPUs. The dilemna is choosing between the Pentium 233 MMX or an AMD K6-2. The AMD CPU is supposed to include the MMX instructions in addition to 3D Now!. My motherboard's maximum clock setting is 75x4 (possibly x4.5) Which is the better deal performance-wise?

I still enjoy playing with the old socket 7 systems. Got a few questions for ya before I can answer your's...

What chipset does the board use?

What CPU voltage settings are available? If you can't lower the voltage to 2.2v, you can't use a K6-2.

Asus A7N8X-X
1800+ @ 8.5 x 200MHz
768MB PC3200 2.5-3-3-7
Asus A9550GE/TD 128MB
WinME/WinXP Pro

With good cooling, a K6-2 can tolerate .2 overvolting with no problems. And one of the best deals going right (sometimes under $10.00) now are the K6-3 400s that show up on ebay. The early ones are 2.4 volts. These would work with a motherboard that goes as low as 2.5. If the motherboard goes lower, the 2.2 450 would be a better choice.

I have my aunt set up with a decapped K6-2+ 450 @550. They are 2.0 default, and it has been running at 2.4 for over two years.

Yes, please tell us the chipset, and/or the make and model of your motherboard. We can offer more advice with this information.

yeah, like jam said old socket 7 systems are fun to mess with and some old games i play are actually just as fun with crappy graphics as modern 3D intensive ones. anyway, an AMD k6-2 will interpret a 2x multiplier as a 6x multipilier. so i suggest get a 450mhz AMD K6-2 and use a 75x2 setting 'cause it will see 75x6, hence giving you 450mhz. thats what i did with the three that i still have to mess with...

"an AMD k6-2 will interpret a 2x multiplier as a 6x multipilier. so i suggest get a 450mhz AMD K6-2 and use a 75x2 setting 'cause it will see 75x6, hence giving you 450mhz"

I was holding off on that info until the CPU voltage issue was settled, but Dragon306 is 100% correct

Asus A7N8X-X
1800+ @ 8.5 x 200MHz
768MB PC3200 2.5-3-3-7
Asus A9550GE/TD 128MB
WinME/WinXP Pro

I ran BIOS Agent 'cause I didn't know much about the motherboard:
- Chipset: Intel Triton 430TX rev 1
- BIOS ID: 09/05/97-i430TX-ITE8679-2A59IV59C

From the searching I did on Google, it looks like the board is a VisionTop VT586TX ITE.

As far as I know (from a jumper-chart printed on the board) the lowest it'll go is 2.8v Looks like that just leaves one option then. :(

"the lowest it'll go is 2.8v"

Stick with the 233MMX & try the FSB at 75MHz...you may be able to get it to run at 266MHz (voltage increase may be necessary)

"Intel Triton 430TX"

The 430TX chipset only caches 64MB of RAM, so it's best not to exceed that amount:

http://www.intel.com/design/chipsets/applnots/memory.htm

Asus A7N8X-X
1800+ @ 8.5 x 200MHz
768MB PC3200 2.5-3-3-7
Asus A9550GE/TD 128MB
WinME/WinXP Pro

I've read that the performance drop when having uncached RAM isn't significant (2% drop). I've got 64 MB already on there and want to add 32 more. Uncached memory is also said to be 20x faster than a swap file working off the HD. Second opinion?

Also...when I tried to overclock my current CPU from 166 to 188 MHz the system would freeze at the Win98 boot screen. It used to overclock to 188 without problems (when I only had 32 MB RAM) and the BIOS check was fine. Do you think I would run into problems with the 233 MMX chip?

The minimal performance drop is 2%, but it can run as high as 40% depending on the application & how far you exceed the cache limit. The Intel link I provided explains how Windows "reads from the top" so if you exceed the limit, Windows will ALWAYS go to the uncached RAM 1st.

It all depends on what you use the system for...if it's just basic computing, stick with 64MB. If you run apps that require more than 64MB, it's better to exceed the cache limit than to run off "virtual RAM" (hard drive) which is MUCH slower

Asus A7N8X-X
1800+ @ 8.5 x 200MHz
768MB PC3200 2.5-3-3-7
Asus A9550GE/TD 128MB
WinME/WinXP Pro

About the overclocking...like I said, you may have to increase the CPU voltage. If it won't boot or is unstable, try it at 2.9v.

Just had another thought...try 225MHz (3.0 x 75MHz). Although the CPU speed is 8MHz less, the system will perform better than at 233MHz because of the higher FSB

Asus A7N8X-X
1800+ @ 8.5 x 200MHz
768MB PC3200 2.5-3-3-7
Asus A9550GE/TD 128MB
WinME/WinXP Pro

I'll keep that in mind then. The only reason I might want to increase the RAM is because I like to run a p2p client once in a while when I'm web browsing. If needed I'll just by 16 MB or less worth of RAM so it wouldn't be so bad.

About overclocking the current CPU; I increased the voltage to 2.9v (after 3-4 failed attempts @ 2.8v) when I overclocked thinking that was the problem but it still didn't help. It wasn't very stable when it did work way-back-when either. Should've expected it though since this is one of the MMXs Intel locked the x3.0 multiplier on. Anyway, thanks for the clarification guys. If you know of any other place besides eBay where I could snag a good deal on a PI 233 MMX post please. :)

I have at least a dozen of those MMX CPUs...166, 200, & 233s.

I don't know if you recall, but there was a "scandal" way-back-when when it was discovered that Intel was relabelling 233MMX CPUs & selling them as 166MMX. When word leaked out, people started buying the cheaper 166MMX & simply "overclocking" them to 233MHz (which wasn't really overclocking because they actually were 233s). That's when Intel began locking the multiplier

Asus A7N8X-X
1800+ @ 8.5 x 200MHz
768MB PC3200 2.5-3-3-7
Asus A9550GE/TD 128MB
WinME/WinXP Pro

i have one i will sell you. contact me if your interested send me an email
Fastnfurious306@yahoo.com