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100mhz FSB MOBO and upgrading to PC133 Memory

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Redstone

Member
Joined
Oct 30, 2002
Supposedly, my MOBO (while not officially) can run PC133 SDRAM memory.
If I stick PC133 memory in my PC100 MOBO and overclock the FSB to lets say 115mhz, would my memory then run at 115mhz?
How about if I leave my PC100 ram in there, and overclock. Can the PC100 memory run at speeds past 100mhz? Can either memory run at speeds past there official speed?
 

ninthebin

Member
Joined
Mar 24, 2002
Location
Liverpool, UK
your memory will run at whatever your fsb is set to. But this also alters the clock of the processor - and if your all intel this is locked so check out what it is.

if your motherboard allows it then it should be dandy for doing this as you shouldnt have to worry...but either way pc133 will work in the mobo so you dont have to oc it :)
 
OP
Redstone

Redstone

Member
Joined
Oct 30, 2002
So do I gain anything by running PC133 at 115mhz over PC100 at 115mhz? In other words is PC133 more stable or faster dropping down than PC100 running over its rated speed?
 

CrystalMethod

Senior Band Wagon Jumper
Joined
Jun 9, 2001
Location
Montreal, Quebec, Canada
Redstone said:
So do I gain anything by running PC133 at 115mhz over PC100 at 115mhz? In other words is PC133 more stable or faster dropping down than PC100 running over its rated speed?

Yes and no, sort of. It really depends on your motherboard, and memory combination. Sometimes you will get an increase, other times you will get a decrease. If you don't understand my statement let me know, I know it's kind of cryptic, but if you know what I'm trying to say there's no real need to go into a detailed explaination.
 
OP
Redstone

Redstone

Member
Joined
Oct 30, 2002
Still lost...

This is new territory for me so no I do not really understand.

You see my Sig. I have the P3b-f 440BX AGPset. If you could explain it great…or at least send me in the right direction to find out.
I’ll upgrade if there will be a straight performance gain, a performance gain after tweaking or stability in overclocking.
 

CrystalMethod

Senior Band Wagon Jumper
Joined
Jun 9, 2001
Location
Montreal, Quebec, Canada
Ok. Here goes. There's the possibility that the PC133 being manufactured today, will not be recognized by your chipset properly. Usually, only half of the installed memory will be detected. Sometimes, the PC133 won't be detected at all. Sometimes you get lucky and the board see all of the installed memory. You're basically taking a shot in the dark. The BX chipsets weren't designed for PC133 or a 133Mhz bus for that matter, so the results of overclocking them are unpredictable at best. If you're willing to put forth the time and effort, you can get it to work. You're working with an outdated motherboard, and CPU. The CPU's interface with the motherboard is 2 generations back, while the motherboard is 3 generations back (soon to be 4). Getting all the components to work together is a task in itself. Getting them to OC and play nicely together,is even harder. This is where you have to ask yourself wether or not it's worth spending the time (and possibly the money) to get it to work, or to just start building a new system.
 
OP
Redstone

Redstone

Member
Joined
Oct 30, 2002
OK thanks,
I am content with my system for now, will hang on to it little longer, and just enjoy optimizing it. From what I have read, I my MOBO does OK with PC133 as long as there is no more than 128mb per side on the memory stick. (Must be where the half detection happens). Since win98 only recognizes 512, two double sided 256 sticks may be compatible.

The system is running very smooth right now moderately overclocked, so if there is no real speed/stability gain by just adding PC133, I wouldn’t do it.
 

Lancelot

Member
Joined
Feb 12, 2001
Location
the Netherlands
In the past I've been running a 128 MB PC133-333 stick and a 128MB PC100-222 stick together @133Mhz FSB without any problems. My mobo is also a i440BX based board (read my siggy) and indeed you need the older type double sided sticks. I think your P3B-F supports a max. DIMM size of 256MB like my Abit board does.
 

TUK101

Member
Joined
Jun 27, 2001
Location
Wash. State
If you have a stick that you could borrow from somebody to test that would be the way to go. Then you could test it out to see if it is worthwhile. The real benefit to getting a stick of PC133 ram would be the increased chance of being able to hit that magical 133fsb for a 33% increase in mhz and still be able to keep the rest of the components in spec. But if you arent wanting to get that high of an OC then I would say to just stick with what you have and build a new system when you are ready and save your money till then. Good luck to you.
 
OP
Redstone

Redstone

Member
Joined
Oct 30, 2002
It’s amazing how far those Cele’s can overclock. My CPU runs borderline cold at 18c idle, 33c under load with a nicely lapped heatsink, and I still can’t get past a consistently stable 1120mhz.

Just to make sure I am understanding what’s being said here, if both types of memory have the same basic bios settings, there really shouldn’t be a difference in system speed. The possible difference is in overclocking. Right?

Since my MOBO can run the PC133, I may slap it in to see if it helps my CPU o/c’s a little further. I like the idea of reaching 133mhz.


p.s. thanks everyone...it's starting to make sense
 
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