ASUS A7N8X and processor speed problem (?)

[Theophylact]

Okay, I've apparently successfully installed this board with a single 512 stick of DDR333 memory and an Athlon 2500+ (Barton, 333 FSB). Everything boots fine; it finds all my drives and the right amount of memory. But the boot screen reports that the Athlon's speed is 1100MHz, or half of what it should be.

The BIOS has processor detect and memory detect both set at [auto].

What's wrong? Or is something wrong?

I don't want to go ahead and install an OS until I get this one figured out.

Sounds like your FSB is set to 100MHz instead of 166MHz.

It's really hard to screw up this board, trust me. Walk into the BIOS and set everything up for the CPU. You'll probably just have to set the FSB universally and it'll work fine.

It should be 11x166 for the CPU. I don't know what kind of RAM you have, try aggressive settings for the memory. Unless it's junk, it'll work pretty well.

[Theophylact]

I assume it is. The boot screen reports memory frequency at 100MHz, single-channel mode.

The memory's a brand-new stick of Mushkin PC2400 non-ECC, unregistered. It should be just fine.

But the first question is "why isn't autodetect working?" (And what exactly do you mean, set the FSB "universally"?)

[Theophylact]

I've upped the FSB to 166, and the boot screen now reports the processor as an Athlon XP 2500+, as it should.

But I'm still puzzled...

[Chiguy]

I guess autodetect doesn't detect the correct FSB speed and thus you need to put it in yourself. It's happened to me before.

By? Give me a couple minutes, I'll check my BIOS settings since we have nearly identical setups.

CPU External Freq. (MHz) [166]
CPU Frequency Multiple Setting [Auto]
CPU Frequency Multiple 11.0x
System Performance [Aggressive]
CPU Interface Aggressive
Memory Frequency 100%
Resulting Frequency 166MHz
Memory Timings Aggressive

It should autodetect all the SDRAM RAS and CAS stuff by then.

[peterwilkes]

The mobo will only auto detect the multiplier of the processor. The processor does not know that it is meant to run at 166 Mhz FSB so it just defaults to 100 Mhz t be safe.

If you set the RAM to SPD it should set it up perfectly with all the correct timings. Try aggressive and you may get a little performance increase.

[Xtreeme]

My 2500+ and A7n8x deluxe pics up fine on auto. Sets the fsb to 166 and the multi to 11x. I oclock enuff to know since I set it back to auto every now and again. The cpu aint telling bios or bios isnt asking-one or the other. The default on that board is 100 unless you set the default fsb jumper near cpu. To support my claims I googled for ya.

http://forums.devhardware.com/t15185/s.html

"Don't forget to check the FSB jumper on your mother board also!
When set to 1-2 (default) supports CPU for FSB 400/333/266.
When set to 2-3 the board supports 200 FSB only! (Old Duron & T-Bird)
Official support for 400 FSB is available on A7N8X PCB 2.0 and later versions only.
back to top"


THe last part he wrote. "Official support for 400 FSB is available on A7N8X PCB 2.0 and later versions only" is actually wrong. The board revision 1.06 and UP support 200fsb but the bios came later to unlock it. Mine goes way above 200fsb in the fsb settings. Higher then would be stable for sure. At 200 its rock solid. Version 1.06 board with newest bios.




If jumper is set..(but I doubt it is)... What bios version you running on that board? If the bios is older it may not recognise that perticular cpu. But my best guess is you skipped over the manual and missed the default fsb jumper on mobo.

[Theophylact]

Originally posted by Xtreeme
If jumper is set..(but I doubt it is)... What bios version you running on that board? If the bios is older it may not recognise that perticular cpu. But my best guess is you skipped over the manual and missed the default fsb jumper on mobo.

Your "best guess" is right; but the default fsb setting (according to the manual) is 400/333/266, and I'm running a Barton 333.