First post, by BurnedPinguin
- Rank
- Newbie
I have an Am5x86 here in a motherboard I recently fixed (https://www.ultimateretro.net/en/motherboards/7273), and right when I did fix it, I saw the L1 on the CPU was running in WT mode. And after some jumper manipulation (thanks Tiido) I managed to get my 256K of L2 working, and thought that would fix the problem and now the L1 would be running in WB mode, but it doesn't. I've tinkered around with the BIOS in every category and I didn't find any settings that switch the CPU's L1 cache mode. Maybe I've missed something, or maybe I could use a software tool to switch to WB mode, which is why I am posting here to see if anyone can help. I've captured the CACHECHK and CHKCPU results in text files, and they are as follows:
CHKCPU (what actually told me that the CPU is in WT mode)
CPU Identification utility v1.25 (c) 1997-2016 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD 5x86-133 P75 (X5)
Internal CPU speed : 133.1 MHz
Clock Multiplier : 4.0
Bus clock speed : 33.2 MHz
CPU-ID Vendor string: AuthenticAMD
CPU-ID Signature : 0004E4
|||||+- Stepping or sub-model no.
||||+- Model: Indicates CPU Model and 486 L1 cache mode
|||+- Family: 4=486, Am5x86, Cx5x86
||| 5=Pentium, Nx586, Cx6x86, K5/K6, C6, mP6
||| 6=PentiumPro/II/III, CxMII/III, Athlon, C3
||| F=Pentium4, Athlon64
||+- Type: 0=Standard, 1=Overdrive, 2=2nd Dual Pentium
|+- Ext. Model: Extends the Base Model to an 8-bit value
+- Ext. Family: Extends the Base Family value
Current CPU mode : Real
Internal (L1) cache : Enabled in Write-Through mode
CACHECHK
CACHECHK v4 2/7/96 Copyright (c) 1995 by Ray Van Tassle. (-h for help)
CMOS reports: conv_mem= 640K, ext_mem= 15,360K, Total RAM= 16,000K
"AuthenticAMD" 486 Clocked at 132.9 MHz
Reading from memory.
MegaByte#: --------- Memory Access Block sizes (KB)-----
1 2 4 8 16 32 64 128 256 512 1024 2048 4096 <-- KB
0: 8 8 8 8 8 26 26 26 26 42 -- -- -- æs/KB
1: 8 8 8 8 8 26 26 26 26 42 42 42 42 æs/KB
2 3 4 5 6 7 8 9 10 11 12 13 14 15 <--- same as above.
Extra tests----
Wrt 40 40 40 40 40 40 40 40 40 40 40 40 40<-Write mem
This machine seems to have both L1 and L2 cache. [read]
L1 cache is 16KB -- 134.8 MB/s 7.8 ns/byte (514%) (315%) 3.9 clks
L2 cache is 256KB -- 42.7 MB/s 24.5 ns/byte (162%) (100%) 12.4 clks
Main memory speed -- 26.2 MB/s 40.0 ns/byte (100%) [read] 20.3 clks
Effective RAM access time (read ) is 160ns (a RAM bank is 4 bytes wide).
Effective RAM access time (write) is 152ns (a RAM bank is 4 bytes wide).
"AuthenticAMD" 486 Clocked at 132.9 MHz. Cache ENABLED.
Options: -t0