cpu FSB and motherboard/memory question

[techiecool]

ok, i am trying to build my first pc. i have decided that i will get an amd 1700 and i don't plan to OC. if the FSB is only 266, then will i see a performance increase by getting memory that is over ddr 266 pc 2100.

 

[ChampionAtTufshop]

not really

however you can lower the multiplier to 9 and raise the fsb to 166 you get ~1494mhz which is pretty close to spec
if its a tbred b 1700+, it will run that no problem
then you can get pc2700 ram (333) and run it in sync wtih the cpu fsb

unless you dont feel like going through all that
then yah pc2100 is perfect

 

[techiecool]

sorry still didn't get it, but i am a newbie to building computers. but i have decided to get a nforce2 mobo w/ amd 1700 cpu. i will not overclock (almost 90%sure, could be fun later though). and the cpu has a 266 bus (correct?) and the mobo (epox/abit not sure which yet) can handle upto 400 Mhz. but doesn't the cpu become the bottel neck? where do you see the advantage of putting in the faster memory in this situation? thanks.

 

[BigBadBiologist]

Yeah, the nForce doesn't really get a whole lot out of running the memory faster than the FSB. So basically, you'd see no improvement if you bought PC2700 (166/333MHz) or PC3200 (200/400MHz) RAM and used your CPU at 133/266 FSB.

The real performance increase occurrs when you synchronously increase your FSB and memory.

However, if you plan on OCing or upgrading some day, I would say to buy the better RAM so that you don't have to buy RAM again in the future.

(numbers in parentheses refer to actual speed/ effective DDR speed)

 

[ChampionAtTufshop]

if you ae not ocing, then theres no point in putting faster ram in unless like said above you plan to upgrade while ddr is still in demand and then you can carry ram over

waht i was getting at, was to change the freq of the cpu (in effect changing the fsb) while keeping it close to the original mhz

an easy example to show you waht i mean
100mhz * 10 = 1000mhz (200fsb) => pc1600
133mhz * 7.5 = 1000mhz (266fsb) => pc2100
166mhz * 6 = 1000mhz (333fsb) => pc2700
200mhz * 5 = 1000mhz (400fsb) => pc3200


if its an xp1700+ tbred b, then you should have no problem running it at 166mhz and a lower multiplier to give you the higher fsb (THEN it would be useful to get faster ram as shown above, as you want to keep ram at a 1:1 ratio ..possibly higher, but AT LEAST 1:1)

 

[wojtekpl]

Originally posted by: ChampionAtTufshop

an easy example to show you waht i mean
100mhz * 10 = 1000mhz (200fsb) => pc1600
133mhz * 7.5 = 1000mhz (266fsb) => pc2100
166mhz * 6 = 1000mhz (333fsb) => pc2700
200mhz * 5 = 1000mhz (400fsb) => pc3200
if its an xp1700+ tbred b, then you should have no problem running it at 166mhz and a lower multiplier to give you the higher fsb (THEN it would be useful to get faster ram as shown above, as you want to keep ram at a 1:1 ratio ..possibly higher, but AT LEAST 1:1)

Now, I don't quite get it... I have Athlon XP 1700+ (the one VERY suitable for overclocking - AXDA 1700 DLT3C 9390257270466 JIUHB 0310 WPMW) which runs 11 x 133 Mhz and DDR memory running at 333 Mhz . Now, I can't change multiplier on CPU (how can I do that?? Schould I have special motherboard or just short some bridges on CPU?? ). All I can do is to change FSB from 133/33 up (134/34, 135/35 and so on, special setting is 166/33).
How can I change the spped of CPU only with memory running it's default speed?
I have Biostar M7VIP motherboard.

 

[AbusedFish]

Originally posted by: wojtekpl

Originally posted by: ChampionAtTufshop

Now, I don't quite get it... I have Athlon XP 1700+ (the one VERY suitable for overclocking - AXDA 1700 DLT3C 9390257270466 JIUHB 0310 WPMW) which runs 11 x 133 Mhz and DDR memory running at 333 Mhz . Now, I can't change multiplier on CPU (how can I do that?? Schould I have special motherboard or just short some bridges on CPU?? ). All I can do is to change FSB from 133/33 up (134/34, 135/35 and so on, special setting is 166/33).
How can I change the spped of CPU only with memory running it's default speed?
I have Biostar M7VIP motherboard.

In answer to your inquery, you're probably not getting good o/c results because that mobo has very bad o/c options. I doubt that mobo can automatically unlock the clock multiplier on your cpu like recent mobos are able to do. If you really want to keep your CPU FSB at default --( I don't know why you would want 133Mhz FSB paired with 166Mhz FSB of DDR RAM because your system will only perform as good as its slowest component)-- You can manually unlock the clock multiplier of your CPU by modifying the bridges, but I would suggest you get a more recent mobo, because they will automatically unlock the multiplier for you, saving you the trouble, and it will most likely out-perform your Biostar M7VIP.

However, if you are tight on cash, you can manually unlock the cpu pretty easily. By the way, you should overclock your CPU FSB to 166mhz (DDR 333Mhz) making it sync with your (333Mhz DDR RAM) if you can, because that would greatly increase performance. It would be better than just overclocking by the clock multiplier alone.

Hope that helps.
:gift:

 

[bgeh]

if possible, change your mobo......but if you're tight, then just set it to 166/33
166 x 11 = 1836MHz

 

[wojtekpl]

yeah, I got Epox 8RDA mobo and the problem has gone .
Though with standard settings 3DMark2001SE doesn't give anything better results than with my Biostar M7VIP mbm.
But now I have plenty of room for OC
Regards
Wojtek