VOGONS


First post, by Kordanor

User metadata
Rank Member
Rank
Member

Hey there!

I am currently using an AMD K2/500 with a Vodoo 3 3500 and it was mentioned in another thread, that the K2+ and K3+ would be a significant improvement.

I know that the K2 with my Ali chip has the cash issue and I can have a maximum of 128MB of Ram without getting a significant performance hit. But I am not sure of more RAM would make that much of a difference.
The issue I mostly seem to have that newer games like Jagged Alliance 2 (1999) seemed to be struggling and hanging (thats not even a 3D game), my guess is that either the CPU is having issues to keep up or the ISA Soundcard is causing issues.
My Goal however is also to be able to downclock as much as possible to keep compatibility with old DOS games. My K6 2 500 can currently be set down to 500 Mhz. Thats done via jumpers, but thats perfectly fine (I built a doohickey do to that externally)

Of course I also looked into some resources, to get more info about potential performance boosts and characteristics but also saw some contradictions.

I saw the Wiki page here: https://en.wikipedia.org/wiki/AMD_K6-III
And that lists the K6-III, K6-III-P, K6-2+ and L6-III
It lists different Front Side bus for all of them. According to the list the K6-3 Only supports a FSB of 100Mhz, but Phil mentioned you can also set it to 66. So that info apparently is incorrect. Source: https://youtu.be/fcAqRbFFQPU?t=730
But does that mean they are all incorrect on the page and can use 66 and 100? For example the K6-2+ only lists 95,97 and 100Mhz
While the L1 Cache is the same on all 4 versions, the L2 cache is not (the K2+ has less), does that have a significant impact? Also only the Plus versions actually have an "extended 3DNow!", which added 5 new DSP instructions". No idea whether that has an impact and on what.

I also checked out Phils video here: https://www.youtube.com/watch?v=A2Oymnq5DEQ
This benchmarks 550Mhz Models of the II and II+ with 550Mhz each against a KIII+ with 400Mhz at 400Mhz and overclocked to 550 Mhz.
But ofc what is missing there are the K6-3 models. Furthermore the boost of the KIII+ with 400Mhz over the K6-II with 550Mhz isn't huge. Sure, there is overclocking, but ofc you can also never guarantee for 1.6v Models you also pay a premium (currently 140€ on ebay for K6-3 400Mhz with 1.6v and 100€ for AHX 2.2V model)
a K6-II+ with 550Mhz on the other hand can be had for "just" 79€, which looks like the safer bet.

I am also wondering why apparently nobody talks about the AMD K6 III without the +. Are the clock speeds too low that they are not worth it while at the same time there are no low voltage options for overclocking? (K6-III is 450Mhz max, and K6-IIIP is 475Mhz max)
There is no coverage and benchmarks at all of those, at least none I have been able to find.
But there I would also be interested in the differences of K6-III and K6-III-P which on that wiki page, look mostly the same.

Appreciate any opinions, comments and leads!

Reply 1 of 4, by brian105

User metadata
Rank Member
Rank
Member

The K6-3 non plus is identical to the K6-3+ in performance. Basically the only 2 big differences are 1. overclocking capability and 2. heat produced, as the plus model uses a smaller node. So if you see a K6-3+ benchmark, it's safe to assume the K6-3 non plus is about the same. The extended 3Dnow stuff probably won't make a big difference.
I think if a game is unplayable on a K6-2, it won't be much better on either plus model.

Presario 5284: K6-2+ 550 ACZ @ 600 2v, 256MB PC133, GeForce4 MX 440SE 64MB, MVP3, Maxtor SATA/150 PCI card, 16GB Sandisk U100 SATA SSD
2007 Desktop: Athlon 64 X2 6000+, Asus M2v-MX SE, Foxconn 7950GT 512mb, 4GB DDR2 800, Audigy 2 ZS, WinME/XP

Reply 2 of 4, by Kordanor

User metadata
Rank Member
Rank
Member

Oki, thanks.

Yeah, I am also more interested in making "barely playable" or annoying stutters go away. I dont expect to be able to play Deus Ex or Ultima 9...guess that would be insane (bot currently at maybe 10 fps). Better for these games to come from the "other side".

Reply 3 of 4, by Repo Man11

User metadata
Rank l33t
Rank
l33t

Now that we know that most K6-2+ CPUs can be modified to have the full 256k L2 cache, everyone can afford a K6-3+ 550. SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod

"We do these things not because they are easy, but because we thought they would be easy."

Reply 4 of 4, by rasz_pl

User metadata
Rank l33t
Rank
l33t
Kordanor wrote on 2023-09-22, 17:00:

newer games like Jagged Alliance 2 (1999) seemed to be struggling and hanging

freezing and crashing or just choppy? you can always turn off audio to verify, but in general I would say you are experiencing period correct behavior for AMD system.

Reproductions
https://github.com/raszpl/FIC-486-GAC-2-Cache-Module for AT&T Globalyst
https://github.com/raszpl/386RC-16 memory board
RE
Zenith Data Systems (ZDS) ZBIOS 'MFM-300 Monitor'