Page 4 of this should be what you need, https://theretroweb.com/motherboard/manual/ga … 6d058353490.pdf
Cyrix models can be a bit variable on their multiplier assignments you might need to set it to 2x to get 4x.

The Results of My Test of these CPU's

K6-2 300

The Multiplier Settings stated by the Manual

Multiplier DIP switches
key:- x means off
o means On

SW 1 2 3
1.5/3.5 x x x
2.0/6.0 o x x
2.5 o o x
3 x o x
4 o x o
4.5 o o o
5 x o o
5.5 x x o

DIP Switches 4,5,6,7,8 adjust voltage but since all three cpu's run on 2.2V theres no point in listing the settings except to say 2.2v is 4 off 5 on 6 off 7 off 8 off

FSB Jumper Settings

Key:-
1-2 = jumper placed on pins 1 and 2
2-3 = jumper placed on pins 2 and 3
x = Remove jumper
o = Install jumper

JP2 JP1 JP14 JP16 Mhz
2-3 2-3 2-3 x 66
1-2 2-3 2-3 o 75
1-2 2-3 2-3 x 83
1-2 1-2 2-3 o 95
1-2 1-2 2-3 x 100
1-2 1-2 1-2 x 105
1-2 1-2 1-2 o 110
For Overclocking Settings beyond this point see original manual as this as far as I could go without crashing.

Since My Board doesnt have JP16
75mhz setting can also automatically set to 83mhz
95mhz setting can also automatically set to 100mhz
105mhz setting can aslo automatically set to 110mhz

95/100 Bus Setting Results

x1.5/x3.5 Sets 3.5x100=350mhz Untested
x2.0/6.0 Sets 3.5x 95 = 333mhz Untested
x2.5 Sets No Post
x3.0 Sets No Post
x4.0 Sets 3.0x 95 = 290mhz 3DMark 2000=815
x4.5 Sets 2.5x 95 = 240mhz
x5.0 Sets 2.5x100=250mhz
x5.5 sets No Post

105/110 Bus Setting

x1.5/x3.5 Sets 3.5x105=366mhz Untested
x2.0/6.0 Sets 3.5x 110 = 380mhz Untested
x2.5 Sets No Post
x3.0 Sets No Post
x4.0 Sets 3.0x110 = 330mhz Unstable
x4.5 Sets 2.5x110 = 275mhz
x5.0 Sets 2.5x105 =266mhz
x5.5 sets 3.0x105 =315mhz 3DMark 2000=1062

Cyrix MII 400

95/100 Bus Setting

x1.5/x3.5 Sets 3.5x100=350mhz PR Rateing 500 Failed
x2.0/6.0 Sets 3.5x 95 = 333mhz PR Rateing 466 Crash during 3D Mark Testing (Memory BSOD)
x2.5 Sets 2.0x 95 = 188mhz PR Rateing 233
x3.0 Sets 2.0x100= 200mhz PR Rateing 233
x4.0 Sets 3.0x 95 = 285mhz PR Rateing 400 3D Mark 2000=1001
x4.5 Sets 2.5x 95 = 237mhz PR Rateing 300
x5.0 Sets 2.5x100= 250mhz PR Rateing 366
x5.5 sets 3.0x100= 300mhz PR Rateing 433 Failed

105/110 Bus Setting

x1.5/x3.5 Sets 4.0x 95 = 380mhz PR Rateing 533 Failed
x2.0/6.0 Sets 4.0x100 = 400mhz PR Rateing 550 untestes as 533 failed
x2.5 Sets 1.5 x110 = 165mhz PR Rateing 233
x3.0 Sets 2.0x1o5 = 210mhz PR Rateing 233
x4.0 Sets 3.0x110 = 330mhz PR Rateing 466 3D Mark 2000=Memory BSOD
x4.5 Sets 2.5x 110= 275mhz PR Rateing 400 3D Mark 2000=980
x5.0 Sets 2.5x105= 263mhz PR Rateing 333
x5.5 sets 3.0x105 = 315mhz PR Rateing 433 Failed

AMD K6-2 500

Bus Setting 75/83

x1.5/x3.5 Sets 3.5x 83 = 290mhz
x2.0/6.0 Sets 3.5x 75 = 266mhz
x2.5 Sets 6.0x75 = 450mhz
x3.0 Sets 6.0x83 = 500mhz 3DMark 2000=635
x4.0 Sets 3.0x75 = 225mhz
x4.5 Sets 2.5x75 = 190mhz
x5.0 Sets 2.5x83 = 210mhz
x5.5 sets 3.0x83 = 250mhz

95/100 Bus Setting

x1.5/x3.5 Sets 3.5x100 =350mhz
x2.0/6.0 Sets 3.5x 95 = 333mhz
x2.5 Sets 6.0x100=600mhz Crashes before Windows
x3.0 Sets 6.0x100=600mhz Crashes before Windows
x4.0 Sets 3.0x 95 = 290mhz
x4.5 Sets 2.5x 95 = 240mhz
x5.0 Sets 2.5x100=250mhz
x5.5 Sets 3.0x100=300mhz

105/110 exactly the same as AMD K6-2 300

Attempted 115/120 Bus Setting x2/x6 (3.5x120=417mhz) crashes before Windows

Conclusions:-

K6-2 300 Is Multiplier Limited to 2.5/3.0 and 3.5 seems to work best on setting x5.5 (105mhzx3=315mhz)
k6-2 500 either the CPU or Motherboard has issues with 4.5/5 and 5.5 Multipliers making it difficult to Set the Specified 5x100 Setting
In fact 4.5/5 and 5.5(the multiplier not the setting) are Missing in any of the tests what on the motherboard would cause such an issue?
Cyrix MII 400 is the only CPU to set its correct Speed Setting albeit that the setting doesnt match the multiplier but that seems to an issue across the board.
Was Dissapointed given the lower heat output of the Cyrix that i wouldnt overclock the same as the K6-2 300 on a 105 Bus. crashing with a Memory BSOD.

Further Conclusions despite the reputation of this Motherboard I wouldnt reccomend it, I think my Favourite Board Was A PC Chips board and your goner hate me for saying so with a SIS 530 chipset, cause all the CPU Setting where done in the BIOS despite the lack of AGP Port, i remmember buying An NVidia RIVA TNT2 32MB PCI card to replace the lacklustre 8MB SIS AGP Onboard Graphics Chip.

I found a similiar board online but he wants a whooping £140 some modern budget boards dont cost that much thats insane.

Hmmm, might need to give the CPU socket and switches a good blast out with air and contact cleaner, and inspect underside of board for any scratches and previous user mods, like check socket pins underneath in case someone bodge wired a multi lock. Then if none of that helps, might be down to inspecting BF0/1/2 traces and checking the pullup/pulldown resistors, checking all the pullups and pulldowns on the clock chip etc.

Heh, and yeah I get that about PC Chips, they didn't spend the extra time and money to STOP you from doing stuff, if you were willing to tinker with settings you could get them running real nice.

Forgot to mention I have no usb ports, the board has a header but the pinout is non standard and it's 8 pin connector not the standard 10 with one missing.

I've been trying to add a pci card but I've bought and tried 2 cards and they both stop the pc booting. So yet another annoying thing about this board.

Does the GA-5AA have some undocumented multiplier options?

I have a K6-III+ 450 that I’d like to overclock to 600 if possible.

The board only has up to 5.5 multiplier but ideally I’d like a 6.0 multiplier.

How do you reach 600MHz on these boards. is it only possible with 110Mhz FSB? (Which may reduce stability as it then affects other devices and not only the CPU)

byte_76 wrote on 2025-04-03, 07:00:

Does the GA-5AA have some undocumented multiplier options? […]
Show full quote

Does the GA-5AA have some undocumented multiplier options?

I have a K6-III+ 450 that I’d like to overclock to 600 if possible.

The board only has up to 5.5 multiplier but ideally I’d like a 6.0 multiplier.

How do you reach 600MHz on these boards. is it only possible with 110Mhz FSB? (Which may reduce stability as it then affects other devices and not only the CPU)

The motherboard doesn’t control the multiplier, the CPU does.

On (Super) Socket 7 boards, the 2 or 3 multiplier jumpers just set a high or low voltage on the CPU’s BF pins. It is then up to the CPU to select a multiplier setting depending on the input level on the BF pins. This is not the same for every socket 7 CPU.

Look at this webpage: https://www.pchardwarelinks.com/cpuspeed.htm
The “Motherboard Multiplier Settings” table on this page clearly shows the wide variation in possible multipliers for various socket 5/7 CPUs.

In this table, you see that the K6-2CXT, K6-III, K6-2+, and K6-III+ are the only socket 7 CPUs that support the x6 multiplier. Simply use the motherboard’s x2 setting to get x6 on these CPUs.

About overclocking a K6-2+/III+, you may need to increase the Vcore one notch to 2.1V and use a good cooler. I would advice against using 2.2V on the K6plus, this stresses the CPU and has shown to cause instabilities in some cases.
So if 600MHz ( 6x100) is not stable at 2.1V, you can try 570MHz (6x95) or 550MHz (5.5.x100) on your K6-III+/450.

Cheers, Jan

Chkcpu wrote on 2025-04-06, 17:46:

The motherboard doesn’t control the multiplier, the CPU does. […]
Show full quote

byte_76 wrote on 2025-04-03, 07:00:

Does the GA-5AA have some undocumented multiplier options? […]
Show full quote

Does the GA-5AA have some undocumented multiplier options?

I have a K6-III+ 450 that I’d like to overclock to 600 if possible.

The board only has up to 5.5 multiplier but ideally I’d like a 6.0 multiplier.

How do you reach 600MHz on these boards. is it only possible with 110Mhz FSB? (Which may reduce stability as it then affects other devices and not only the CPU)

The motherboard doesn’t control the multiplier, the CPU does.

On (Super) Socket 7 boards, the 2 or 3 multiplier jumpers just set a high or low voltage on the CPU’s BF pins. It is then up to the CPU to select a multiplier setting depending on the input level on the BF pins. This is not the same for every socket 7 CPU.

Look at this webpage: https://www.pchardwarelinks.com/cpuspeed.htm
The “Motherboard Multiplier Settings” table on this page clearly shows the wide variation in possible multipliers for various socket 5/7 CPUs.

In this table, you see that the K6-2CXT, K6-III, K6-2+, and K6-III+ are the only socket 7 CPUs that support the x6 multiplier. Simply use the motherboard’s x2 setting to get x6 on these CPUs.

About overclocking a K6-2+/III+, you may need to increase the Vcore one notch to 2.1V and use a good cooler. I would advice against using 2.2V on the K6plus, this stresses the CPU and has shown to cause instabilities in some cases.
So if 600MHz ( 6x100) is not stable at 2.1V, you can try 570MHz (6x95) or 550MHz (5.5.x100) on your K6-III+/450.

Cheers, Jan

Thank you for this info. This is very helpful and gives me a few options to play around with.