Can A7N8X Deluxe with 2700+ work with only DDR 266 ram?

  • Thread starter Thread starter Daniel Czajko
  • Start date Start date
D

Daniel Czajko

I'd like to put a new CPU in my A7N8X. A 2700+ to be exact. This CPU runs
at 333 Mhz bus, but I only have DDR 266 ram. Can this configuration work?
Can the mobo take a 333 cpu and only 266 ram, or do I have to buy 333 ram to
match the cpu bus?

thanks
 
I'd like to put a new CPU in my A7N8X. A 2700+ to be exact. This CPU runs
at 333 Mhz bus, but I only have DDR 266 ram. Can this configuration work?
Can the mobo take a 333 cpu and only 266 ram, or do I have to buy 333 ram to
match the cpu bus?

thanks
Click to expand...

You don't have to match the cpu bus, but for best stability and
performance it would be better to do so.

Ed
 
Hello Ed,

You don't have to match the cpu bus, but for best stability and
performance it would be better to do so.

Ed
Click to expand...
I own a mobo with a bios that offers the opportunity to set different
values for memory and cpu(fsb) velocity. In such a case will there
still be question of less stability?
And if -with my mobo- I have put in memory that is quicker than the
fsb?

Thanks,

Max M.
 
You can run asynch with 166/333 for the CPU and
133/266 for the memory but best performance will
be in synch mode ie both 166/333

If you have good quality memory it will most likely
run at 166/333 with a little more voltage say 2.7 or 2.8

I have used Crucial memory PC2100 at PC2700 on a couple of systems without
problems but only in single
channel mode.

Hope this helps
Chris
 
Daniel Czajko said:
I'd like to put a new CPU in my A7N8X. A 2700+ to be exact. This CPU runs
at 333 Mhz bus, but I only have DDR 266 ram. Can this configuration work?
Can the mobo take a 333 cpu and only 266 ram, or do I have to buy 333 ram to
match the cpu bus?

thanks
Click to expand...

Assuming that the internal clock multiplier of the CPU is locked, and
you are not going to attempt to unlock it, then if you run the bus
clock at 133 MHz, rather than 166 MHz, the CPU will be running slower
than it is capable of running, but it will still run fine. The actual
internal clock rate of the CPU is the external clock rate times a
multiplier. If the multiplier is fixed, then the internal clock rate
will decrease in proportion to the external clock input. If you can
unlock the multiplier, then you can increase that to compensate for
the decreased external clock.

I'm not certain, but the only problem I could foresee is the reverse
situation. For example, if you have PC3200 memory that is designed to
run at a 200MHz bus clock (400 MHz data rate) and you run it at 133
MHz instead, then the actual time intervals between RAM refresh cycles
will be 70% longer. This may put it out of spec and you run the danger
of losing data in the RAM. This is probably a long shot, but it is the
only possible glitch I could imagine.

Arnie
 
Back
Top