FSB Speeds...

  • Thread starter Thread starter Kedrid
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Kedrid

I just put together a new system. was pretty flawless. I have built a lot of
older systems.. this one is a P4 2.66 533 FSB.. w/ a L4VXA2 " ECS Elitegroup
" motherboard.. supports 533 fsb.. but I got cheapo " Patriot 512M 184pin
DDR400 memory!!

ok in the past you had to match the memory w/ the FSB w/ SDram..( or that
was the case w/ an old PIII 533 on a soyo board I made.. )) so to get a
133Mhz FSB you had to buy 133 memory, I figure I should at least however get
400Mhz fsb. it shows only 133!! ;( there is a motherboard jumper for 533.
is this likely to blow up my memory? or give unstable conditions? or would
it maybe just be a luck thing? some memory can handle it some cant? or w/
DDR is that independent of FSB??

the system runs good. but It don't seem a lot faster then my old P3 533..
lol maybe I am expecting to much??
 
I just put together a new system. was pretty flawless. I have built a lot of
older systems.. this one is a P4 2.66 533 FSB.. w/ a L4VXA2 " ECS Elitegroup
" motherboard.. supports 533 fsb.. but I got cheapo " Patriot 512M 184pin
DDR400 memory!!

ok in the past you had to match the memory w/ the FSB w/ SDram..( or that
was the case w/ an old PIII 533 on a soyo board I made.. )) so to get a
133Mhz FSB you had to buy 133 memory, I figure I should at least however get
400Mhz fsb. it shows only 133!! ;( there is a motherboard jumper for 533.
is this likely to blow up my memory? or give unstable conditions? or would
it maybe just be a luck thing? some memory can handle it some cant? or w/
DDR is that independent of FSB??

the system runs good. but It don't seem a lot faster then my old P3 533..
lol maybe I am expecting to much??
Click to expand...

The "533" FSB of a P4 is actually a quad-pumped 133MHz clock rate.

The memory needed for that system would be DDR, so it's a
double-pumped 133MHz clock rate.

In other words you needed at least PC2100 memory, and any faster
memory may only run at PC2100 speeds unless you have specific bios
support to increase the memory clock rate.

The memory you mention is running at correct speed at "133MHz" as
reported in the BIOS. As for the sluggishness, did you replace the
hard drive? That's often the slowest part in a PC.
 
yea, and its not sluggish so much, as just not the performace boost I
expected for over a 4X CPU speed boost.. lol I expected to see faster
performace..

so w/ DDR400 the best FSB speed I can expect to see is 133 fsb??? so then
switching the mobo jumper from auto to 533fsb would ( in this case ) be
bad!?? lol prob burn up my memory chip, since the rest of the system says
its supports 533 FSB..
 
yea, and its not sluggish so much, as just not the performace boost I
expected for over a 4X CPU speed boost.. lol I expected to see faster
performace..

so w/ DDR400 the best FSB speed I can expect to see is 133 fsb??? so then
switching the mobo jumper from auto to 533fsb would ( in this case ) be
bad!?? lol prob burn up my memory chip, since the rest of the system says
its supports 533 FSB..
Click to expand...

The motherboard runs at the speed set by bios or CPU. The memory only
dicates the timings. If the memory can't support the speed set by the
board the system simply won't run or will err.

DDR400 is of no benefit to you unless you want to (and are able)
overclock.

The motherboard jumper, as I mentioned previously, would be setting
the same speed you're already running, 133MHz clock rate as
quad-pumped (4X), ~533. 533 is not the clock rate, it is the data
rate.

Data Rate / 4 = clock rate
clock rate * 2 = DDR rate
clock rate * 16 (rounded off) = minimum "PCnnnn" rate needed for
synchronous bus clock rate
 
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