VOGONS

Search

Common searches

Cyrix 5x86 at 16.6Mhz with 8.3Mhz fsb.

Topic actions

First post, by cyclone3d

Posted on 
User metadata
Rank l33t++
Rank
l33t++

I have been messing around with my ASUS PVI-486AP4 motherboard. In doing so, I added the 3rd fsb jumper which was set via soldered jumper from the factory.
Re: ASUS PVI-486AP4 motherboard fsb jumpers?

Playing around with it today with a Cyrix 5x86 120, I accidentally found that this board can go all the way down to an 8.3Mhz fsb.

I decided to start a new thread though just for some 8.3Mhz fsb fun.

Here are the benches I ran... and to have screenshots as proof.

Except for the first screenshot, both caches are disabled and the timings in BIOS are set to the slowest possible.

Sorry for the super dusty monitor.. I need to go to bed and didn't want to spend extra time running the benches tonight.

CPU.jpg
Filename
CPU.jpg
File size
308.26 KiB
Views
272 views
File license
Public domain
sysinfo.jpg
Filename
sysinfo.jpg
File size
616.31 KiB
Views
272 views
File license
Public domain
speedsys.jpg
Filename
speedsys.jpg
File size
542.91 KiB
Views
272 views
File license
Public domain
speedsys_ram.jpg
Filename
speedsys_ram.jpg
File size
850.27 KiB
Views
272 views
File license
Public domain
cachechk.jpg
Filename
cachechk.jpg
File size
673.51 KiB
Views
272 views
File license
Public domain

Yamaha modified setupds and drivers
Yamaha XG repository
YMF7x4 Guide
Aopen AW744L II SB-LINK

Reply 1 of 4, by Tiido

Posted on 
User metadata
Rank l33t
Rank
l33t

A lot of boards have PLLs with settings available for really low speeds, meant for laptop power save scenarios. Usually only 3 or 4 settings are ever documented (25, 33, 40, 50) but there's often 4 more settings that have various slow speeds. I have one board that had 4MHz available but at that speed keyboard stopped working, it was interesting to see the memory count go in pretty much slow motion 🤣

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 2 of 4, by cyclone3d

Posted on 
User metadata
Rank l33t++
Rank
l33t++

Nice. I guess I should have mentioned it in the OP... the 8.3Mhz fsb isn't available via the fsb jumpers. It has to do with removing the CPU multiplier jumper while the system is running.

See the other thread for specifics.

I need to do some more investigating.

Speedsys shows lower RAM speed but slightly higher CPU speed when the CPU is running at 16.66 x 3 when compared to 8.3 x 2

Landmark shows the CPU being slower when running at 16.66 x 3 when compared to 8.3 x 2

The 2.5x and 2x CPU jumpers can be added back when the system is on (after removing the jumper when the system is running) and they speed up the system slightly differently.

Yamaha modified setupds and drivers
Yamaha XG repository
YMF7x4 Guide
Aopen AW744L II SB-LINK

Reply 4 of 4, by cyclone3d

Posted on 
User metadata
Rank l33t++
Rank
l33t++
The Serpent Rider wrote on 2020-10-10, 09:00:

But can it run Crysis?

With a score of 4.6 in 3dbench with a VLB video card I don't see why not 😉

Yamaha modified setupds and drivers
Yamaha XG repository
YMF7x4 Guide
Aopen AW744L II SB-LINK

Go to top of page Go to top of page
Back to General Old Hardware
Close window
Close window