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memory question. *please reply*

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mage_x

Member
Joined
Oct 29, 2002
ok my friend bought some pc3200 ram and has a xp2200(133sb)

now this means his ram is running at pc2100 speeds right? 266 mhz?

if he wanted it to run at pc3200 speed hed have to set his fsb 200, am i correct?

he says im not correct and is convinced he is running pc3200 speeds but he needs the proof from someone reliable.
 

ntpphong

Member
Joined
Oct 12, 2002
Location
CA
yes... if his cpu can handle that HUGE overclock.... 200x13.5= 2.7Ghz.
if he wants to go up to that fsp (which i doubt because the 200fsb gonna mess up his pci devices due to the FSB:pCI divider), then he would have to lower his cpu-multiplier.

Experts, correct me if i'm wrong =)
 

Rcoe

Member
Joined
Jul 20, 2001
Location
Michigan
Yes and no. It will depend on what MB he is using. If it is a kt333 or kt400 he will be able to run the memory at a faster speed than the cpu ie 166for333 or 200for400.

If he doesn't have one of these boards he can turn up the fsb, which will inturn raise the entire system bus.

To really take full advantage of the faster memory he will need one of the newer kt333/400 or Nf2 boards.
 
OP
mage_x

mage_x

Member
Joined
Oct 29, 2002
hes using kt400, also is it true that kt400 unlocks tbreds?
 

GosuWar

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Oct 30, 2002
Location
New Jersey
Uhm, The kt400 board would not say that it SUPPORTS 3200 DDR if it DIDN'T support 3200 DDR unless it was over clocked.
 

Stumpjumper5200

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Sep 24, 2002
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Best 1/4 Mile Time: 13.57 @ 101.13
Set the ratio!

Ok, I'm not sure what it might be running on now, but......
set the CPU:memory ratio at 4:5 and you'll have DDR333(pc2700)
set the CPU:mamory ratio at 4:6 and you'll have DDR400(pc3200)

bada bing bada bang bada boom, simple.
 

Caffinehog

Übercaffinated Member
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Dec 27, 2001
Location
In the lab
That board will run the memory just fine at pc3200 speeds. BUT the processor won't be able to use more than the bandwidth of a pc2100 unless the FSB is set higher.
That board is definately capable of 166fsb at the bare minimum, but the processor won't be without unlocking. Do a search on unlocking thoroughbreds and you'll see how simple it really is.

Try it at 166fsb X 11mult = 1833mhz. (the processor will barely be out of spec.) This will improve performance a lot, and barely overclock the cpu. And your processor will be able to utilize up to pc2700 speed. With a little luck, you might reach 200fsb X 9mult = 1800 mhz, and your processor will be utilizing the memory's full bandwith of pc3200.
Then see if higer multipliers, like 9.5, or possibly 10 will work. 33fsb makes a lot more difference than 100mhz of processing power.
 
OP
mage_x

mage_x

Member
Joined
Oct 29, 2002
the thing is though hes using the stock hsf w/ a thermal pad and his idle is 50c so i told him not to oc anything til he got a better hsf.
 

Garfield

Member
Joined
Dec 1, 2001
Location
New Jersey
So lemme get this straight...

If you set the ratio so that the memory is running at higher than the CPU (like a 4:5 ratio) then the CPU can't even use that higher memory speed? I don't understand... :confused:
 

Stumpjumper5200

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Sep 24, 2002
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Best 1/4 Mile Time: 13.57 @ 101.13
Well it depends, on AMD systems, yeah. The bus is 133mhz (effectively 266mhz in terms of data transfer) so going beyond that doesn't help much.

Intel on the other hand has a 133mhz but is an effective 533mhz. Intel's have LOTS more memory bandwidth, especially if you decide to go with RDRAM, but good DDR is really catching up.
 
OP
mage_x

mage_x

Member
Joined
Oct 29, 2002
whats the point in setting the ratio to ram higher than cpu if the cpu cant use it without raising the fsb?
 

Placid

Senior Member
Joined
Mar 13, 2001
Location
Connecticut
You might gain a small amount of memory bandwith depending on the cpu you use.
Other than that it helps sell motherboards.
 

Caffinehog

Übercaffinated Member
Joined
Dec 27, 2001
Location
In the lab
mage_x said:
whats the point in setting the ratio to ram higher than cpu if the cpu cant use it without raising the fsb?
With AMD, not much. You may counteract a few tiny inefficiencies in the memory, but the improvement is like 2% or less.
Now increasing the FSB will give proportional performance boosts.

Unlocking and raising the FSB is not going to increase the heat produced by the processor provided you keep the speed the same. You won't notice a temperature difference if you overclock an 1800mhz processor to 1833mhz (11 X 166). On the other hand, the memory bandwidth increase will give you a noticable improvement in performance.
 
OP
mage_x

mage_x

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Joined
Oct 29, 2002
ive heard somewhere else on this forum that kt400 boards automatically unlock tbreds.. is this true?
 

LittlePiggie

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Sep 30, 2002
Location
Oregon
no, to unlock a tbred, you need to connect the L1 bridges.

Do a search for it.

Correct me if I'm wrong people ;)
 

Caffinehog

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Joined
Dec 27, 2001
Location
In the lab
Actually, to unlock a T-bred, you only have to connect one bridge. I think it's an L3, but that's unimportant.
My research shows that this board does, indeed, unlock t-breds. It also has the 1/5 pci divisor. That means that at 166fsb x 11, the only thing running out of spec will be parts of the motherboard. And considering the imminent release of 166fsb t-breds, it's probably designed to work just fine at that speed.
172fsb x 10.5 should easily be achievable. 180fsb x 10 should work fine in most cases. 190fsb x 9.5 should be possible in a good portion of systems. 200fsb x 9 should be possible with good hardware and a little luck. Some people might achieve 212fsb x 8.5, but that's pushing it. None of these settings will significantly increase the heat produced by the processor, so they are safe with a stock heatsink. I suggest trying these out in the order I posted them. BUT back up your data first! When you push the pci bus to its limits, it has a tendency to corrupt the data on your hard drive. There will be no physical damage, but gigs of mp3's can be lost. If you don't want to worry about this, 166fsb x 11 should be safe, because the 1/5 divisor will keep it at default. It's also pretty safe to assume that 172fsb x 10.5 will be fine, too, since you will be running it only 3% out of spec. What you get beyond that will be highly dependent on your hard drive and any PCI cards you have, as well as your video card.