i'm newbie in this section..
i got a problem when install my new RAM [Corsair high Performance DDR400 512M pair]

this feature my PC
intel pentium 4 1.8G sockect 478
mobo Asrock P4i65G

when I enter bios..go to advance option.RAM set to only 266.[why not 400].i cannot setting my RAM..already disable...

what kind of problem i face..or something about setting?

Need help..

Older boards automatically slow down the ram to match the procs fsb (if I'm not mistaken, correct me if I'm wrong experts!!!). I have kingston DDR400 value ram(taken from my main AMD X2 rig) running in an older P4 rig. It has been automatically downclocked to DDR266 as well. But that just means you can probably oc like crazy with the ram since your ram is rated at 400mhz, although you'll have to loosen your timings in my case (once again correct me if I'm wrong).

yea you are right. The RAM will downclock itself to match the processor FSB.
But then, I dont see a need to loosen timing there though

Well I havent tried oc-ing but I think if you oc with value ram you'll have to loosen the timings coz the SPD settings are tighter at ddr266. Mebbe I'll give it a shot later.....see wat this northwood 2.6ghz can reach

what mean united overclocking technology on the my mobo.. so,,i cannot up my RAM?

thanks for ur reply

Yeah, in fact I think it mightr even be possible to tighen the timing.


The board will not allow you to set the ram higher than a certain speed unless the fsb is high enough; and the fsb cannot be raised without overclocking the processor. If your processor is a Northwood (probably is, use CPU-Z to check) then you should be able to increase the FSB to at least 133MHz (533) and get a ram speed to 266 (x2 of 133 because its Double Data Rate). Note that there is absolutely no point in setting the ram faster than the fsb because the processor will not even be able to access the memory that fast due to the fsb limit.

Some equations to consider

processor speed = fsb x processor multiplier

fsb transfer rate = fsb x4 (because the data transfer is quad pumped)

so if the ram is running at the fsb speed
ram transfer rate = fsb x2 (double data rate) x2(if dual channel, which you should be since you're using a 865 chipset and have a pair of ram)

Just increase your procs fsb to oc. You shudnt have any probs since your ram is rated at 400mhz . But I guess your using an old board so you better make sure it has a pci/agp lock 1st. Mine doesnt. You can screw up your hardrives and gfx card if your mobo doesnt have the lock.

This post has been edited by joe_star: May 25 2007, 12:08 PM

i think his mobo that asrock...just can support for DRAM freq just DDR266...
the latency jst only 2.5 the highest can setting....

the corsair ram he use is ddr 400 that latency 3.0-3-3-8

for mst setting this latency in mobo but asrock 478 jst can setting only ddr333 that latency is 2.5-3-3-7...

so can ka after we update bios the dram freq can setting until drr400

thanks bro 4 ur reply...

i try overclock my processor and up to 2066.8 MHz..from initial 1800MHz.. and speed RAM is 153.1MHz x 2...this mobo does't no allow to set timing 3-3-3-8...in bios juz have 2 and 2.5 only...can i have another way to up my RAM to 200MHz x 2....

You board supports fsb of up to 200 (800) and ram up to DDR400 even without overclocking. But even then, there is no point in setting your ram higher than the fsb-there will be no significant performance increase, even in benchmarks. At your current overclock(115x18), the ram will not show any performance increase beyond 115Mhz (DDR230).