CPU clock

I am having a problem with my first home-built system. I am running:
2.00 gigahertz AMD Athlon XP
128 kilobyte primary memory cache
256 kilobyte secondary memory cache

ABIT VA-20 VIA KM400A MB MICRO-ATX mobo
XP Pro
if I go into bios-frequency/voltage control-CPU clock, the allowable range maxes at 199 but I can set it at the reccomended 200Mhz setting, and it works fine. However, everytime I restart, it goes back to a lower setting, 144, I think. The processor is supposed to run at 200, and the difference in performance is dramatic. How can I get it to stop resetting every time I reboot? It's frustrating to have to keep going into bios every time.

 

Do any other bios settings change? If so, check that the clear cmos jumper is not in the clear position. Also, even a new board may have been on the shelf so long it could have a weak battery. When the bios forgets your settings, a weak battery is the first thing to check.

What happens if you set it to 199? Or even less? Does it stay there? It is possible that your board thinks 200 is to high and therefore resets to protect itself ( you say 199 is max allowable )

 

Thank you for your response. No other settings change that I'm aware of. I'm sure the jumper is not in the clear position. I tried setting it at 199, and the system did not like it at all. I got a black screen, no start up bios, no nothing. I had to reset the bios to get it to do anything.

 

Hi,

You could download the AMD CPU identification tool (amdcpuid.exe)
http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_871_2364,00.html
(I see there are other tools now for reading settings.)

Motherboards from that period had a jumper that was set to 150Mhz. You need to change it to the 200Mhz setting. I will check the motherboard manual later today.

Matt

 

I downloaded the utility, and it offers a lot more info than I know what to do with.
If you are talking about the jumper I think you are, is it the CPU FSB Frequency? it has four positions. 110 mhz, 133 mhz, 166 mhz; 200 mhz. It came set at 133. I tried setting it at 200 several times, but I always get black screen, no bios, etc.

 

What is the model of the athlon? There's no 2GHZ in a model name.

 

AMD Sempron 2800+ Socket A

Sorry about calling it Athlon. I copied the stats from belarc, and I didn't catch that.

 

Supposed to operate at 1.6GHZ. Best not overclock it.

 

Thank you for the info. The guy at the store where I bought it said it was supposed to run at 2 GH, and I never questioned that. That would also explain the FSB frequency not working at 2, wouldn't it?

 

I'm sorry, too. Was looking at socket 754. socket A IS supposed to run at 2GHZ. So... if the motherboard recognizes it, it should set it up automatically (if it's a fairly recent board).

Edit: BTW, was it in a retail box with heatsink and fan assemply?

 

The mobo always wants to run it at 1.6. I can sett it to 2, but it always goes back to 1.6 on reboot. The jumper setting for 2 does not work either. I only paid $55 for the mobo. If I have to move up to a better one, I won't be too upset.

 

Well there's no guarantee, and I don't believe you'll feel the difference in performance at the different speeds, so I'd leave it at the mobo's setting if it's working. I've run a 1GHZ athlon for years and work on mostly faster machines and I was happy til I had to change when the mobo died.

 

The difference between 1.6 and 2 is really noticeable on this machine, but I've been using it at 1.6 most of the time for the last 6 months so it'll have to wait until I can afford to upgrade. Thanks for all your help.

 

I wondered if the CPU may be too "new" for the motherboard. There are only two BIOS ugrades for the motherboard and neither relate to CPU identification.

I wonder now if the RAM is suitable to run at 400Mhz (2 X 200Mhz). Is it PC3200? It may not like the RAM running at that speed. You may want to try the RAM in a different slot.

If you want to investigate further, try one of the overclocker's forums.

Matt

 

That would make sense. I have 512 meg of ram, and I suspected it was old stock when I bought it. It may be much older than I thought. I don't know what it is. I'll try to identify it when I move it to the other slot. It's in slot 0 now.

 

I moved the stick to the other slot. No change. I don't know if it's PC3200. the sticker says:
512 MB, DDR DIMM,N
64TND PO 120141.2
made in USA

 

Everest.exe should identify the RAM. Type it into google and you'll find it to download free.

Check under motherboard > SPD.

 

o.k. I got Everest. My memory stats:


[ DIMM2: SpecTek (512 MB PC2700 DDR SDRAM) ]

Memory Module Properties:
Module Name SpecTek
Serial Number 181258EAh
Manufacture Date Week 38 / 2004
Module Size 512 MB (1 rank, 4 banks)
Module Type Unbuffered
Memory Type DDR SDRAM
Memory Speed PC2700 (166 MHz)
Module Width 64 bit
Module Voltage SSTL 2.5
Error Detection Method None
Refresh Rate Reduced (7.8 us)

Memory Timings:
@ 166 MHz 2.5-3-3-7 (CL-RCD-RP-RAS)
@ 100 MHz 2.0-2-2-5 (CL-RCD-RP-RAS)

Memory Module Features:
Early RAS# Precharge Not Supported
Auto-Precharge Not Supported
Precharge All Not Supported
Write1/Read Burst Not Supported
Buffered Address/Control Inputs Not Supported
Registered Address/Control Inputs Not Supported
On-Card PLL (Clock) Not Supported
Buffered DQMB Inputs Not Supported
Registered DQMB Inputs Not Supported
Differential Clock Input Supported
Redundant Row Address Not Supported

Memory Module Manufacturer:
Company Name Micron Technology, Inc.
Product Information http://www.spectek.com/menus/memory_module.asp

 

Looks like that's the reason mobo won't take 200.

 

Which stat indicates a problem? Will adding another stick help, or do I need to replace it with something different?