Mobile Barton, how to enable 400MHZ FSB?

[Ichinisan]

My Mobile Barton is clocked at 2.2 GHz (200FSB, 11xMultiplier). I just installed two PC2100 modules, and the board reports that it is running in dual-channel mode, but it won't allow me to set the CPU to 400MHZ FSB. I thought that two DDR200 modules could run in dual-channel mode to enable 400MHZ FSB. Is DDR266 not capable of running at DDR200 speed?

Asus A7N8X-E Deluxe - NVIDIA nForce2 Ultra 400
2x256MB Corsair DDR266 PC2100

 

[OS]

Originally posted by: Ichinisan
My Mobile Barton is clocked at 2.2 GHz (200FSB, 11xMultiplier). I just installed two PC2100 modules, and the board reports that it is running in dual-channel mode, but it won't allow me to set the CPU to 400MHZ FSB. I thought that two DDR200 modules could run in dual-channel mode to enable 400MHZ FSB. Is DDR266 not capable of running at DDR200 speed?

A7N8X-E - NVIDIA nForce2 Ultra 400

You need DDR400 ram to run 400 FSB (200 mhz double clocked) in sync. How many sticks of ram you have, have almost nothing to do with the bus speed you want to run.

 

[Ichinisan]

That's the point of dual channel. Two sticks running together to double the thoroughput. I should be able to set the processor at 400MHZ FSB

 

[OS]

Originally posted by: Ichinisan
That's the point of dual channel. Two sticks running together to double the thoroughput. I should be able to set the processor at 400MHZ FSB

You go ahead and keep thinking that, while trying to run your PC2100 at 400 MHZ FSB.

You know that phrase about watching the dog chase it's tail?

 

[Ichinisan]

So DDR400 is truly 400MHZ, but DDR266 is only 133MHZ?

Why couldn't they both run at 100, effectively 200 in dual-channel mode, effectively 400 by "Double Data Rate" spec?

Or is it that you *need* DDR400 *AND* dual channel to enable 400MHZ FSB?

 

[OS]

Originally posted by: Ichinisan
So DDR400 is truly 400MHZ, but DDR266 is only 133MHZ?

Why couldn't they both run at 100, effectively 200 in dual-channel mode, effectively 400 by "Double Data Rate" spec?

Or is it that you *need* DDR400 *AND* dual channel to enable 400MHZ FSB?

DDR400 = 200 mhz actual clock, but double pumped (400 mhz effective) = PC3200
DDR266 = 133 mhz actual clock, but double pumped (266 mhz effective) = PC2100

The bus speeds you see in BIOS setups are typically true/actual clockrates, you need to double those numbers to get effective bus speeds.

double channel has nothing to do with bus speed. You can run dual channel at whatever speed you want to as long as the memory and cpu can meet the spec you want to run.

 

[Ichinisan]

I already knew that DDR400 is technically 200MHZ, but it's still not making sense. How would I reach 400MHZ FSB if DDR400 is still only 200MHZ?
Does 400MHZ FSB *require* dual-channel DDR400?

 

[0roo0roo]

yup, dual channel is a bonus, it has nothing to do with bus speed. ur ram runs at its speed. mobile barton is 133mhz 2100ddr aka 266mhz bus .. its rather convoluted, bastids shoulda stuck with the ddr mhz rating for simplicity. to run at ddr 400(200mhz) u need to overclock that barton at that bus speed. or lower the multiplier so u can run that ram speed without the rather high overclock. overclockers.com probably has stuff on it. i dunno if its locked now, i haven't dabbled in it for a while. ur mb might be able to control multiplier if your lucky. i used a cheap ecs mb so i had to cut bridges and do socket pin mods and that sort of craziness . and if ur barton really is 2.2ghz, then its 16.5x X 133mhz.

 

[0roo0roo]

i looked it up. the mobiles are still at 266mhz bus (133mhz ddr ram) pc 2100 bleh blehblah http://www.newegg.com/app/Sear...p?Submit=Go&DEPA=0
if laptops had 400mhz bus cpus(esp this low end cpu).. the mem would be expensive. so doubtful it would be popular or out right now, not worth it. anyways your numbers don't make sense. if ur really at 2.2ghz @200mhz(unlikely overclock for ur ram), then the default speed would be 1.4ghz. i don't see a 1.4ghz mobile.

 

[EpsiIon]

The FSB is "double pumped," too. It's actually at 200 MHz, but can perform operations on both the rising and falling edges of the clock.

To help you better-understand:

-----------------------------------
"Normal (Not DDR) Operation"
-----------------------------------

Quick note: The ops could be on the falling edge, too. It's implementation (and standard) specific.

Clock ( increasing time --> ):

X Volts     ___        ___     
0 Volts__|      |___|      |__
................Op........Op.........




-------------------
"DDR Operation"
-------------------

Clock ( increasing time --> ):
X Volts     ___        ___      
0 Volts__|      |___|      |__
...............Op..Op..Op..Op..



The clock runs at the same speed (from which you can find MHz), but twice as many operations are performed per unit of time (hence Double Data Rate).

I hope you appreciate this, BTW, because it took a while to type. 🙂

 

[Anubis]

11x200? did you manually change that? because my mobile 2400+ defaults at 1.8GHz 13.5x133 (DDR 266, PC 2100)

if you simply change the bus speed to 166 its 13.5*166=2.24GHz (DDR 333, PC2700) and thats the easyest overclock ever, which is why the chip is so popular

if you are running it at 11x200 = 2200 thats a pretty damn good OC for PC2100 ram,
however you will get more out of it if you run the ram a lil slower and up the multplyer

mine is at 2.5GHz right now 13.5*185 = 2.49GHz useing PC 2700 ram 2x 512, Shuttle AN35N Ultra 400

 

[Ichinisan]

OK, so I'm already running at 400FSB then!

Anubis:
It doesn't "default" to anything. Most desktop boards do not recognize the Mobile Bartons. Mine is a mobile Barton 2400+. My Asus K7N8X-E Deluxe reports "unknown CPU type 2200MHz" on the POST scren. My Shuttle XPC SN45G (same CPU) reports "Unknown Type" also, and a thread of conductive wire had to be placed in two holes of the socket so that the Shuttle board could set the FSB properly.

These processors are completely unlocked and cream-of-the-crop, easily clocking far higher than Athlon XP 3200+ CPUs with stock cooling. AMD has bin-sorted these processors and rated them far lower than their capability because they are to be used in mobile systems, which need to run cooler and consume less power than their desktop counterparts.

They really are the best 32-bit CPU's that you can spend your money on.

http://www.newegg.com/app/View...=19-103-400&depa=0

I'm not sure if my RAM is actually overclocked or not. It's probably running in asynchronous mode, allowing me to set the processor FSB higher than the memory is actually running. I'm not sure how that works or even why it's an option...?

 

[Anubis]

ahh must be the moatherboard then, my Shuttle AN35N Unltra 400, same chipset as yours defaulted it to 1.8GHz 13.5*133 like i said above, i figured most did that

and from that newegg page "Operating Frequency: 1.8GHz" so i could be right, you most likely are running in async mode, or y ou have the best pc2100 ever, see if you can run it at a higher multyplier and get even more out of the chip, as long as you are keeping the ram locked down it shoudl work

 

[big4x4]

Originally posted by: Anubis
ahh must be the moatherboard then, my Shuttle AN35N Unltra 400, same chipset as yours defaulted it to 1.8GHz 13.5*133 like i said above, i figured most did that

and from that newegg page "Operating Frequency: 1.8GHz" so i could be right, you most likely are running in async mode, or y ou have the best pc2100 ever, see if you can run it at a higher multyplier and get even more out of the chip, as long as you are keeping the ram locked down it shoudl work

My shuttle board recognizes my mobile barton

 

[Ichinisan]

Are you using a Shuttle Small Form Factor (SFF) board, or a full-size (ATX) board?

 

[CZroe]

Originally posted by: Anubis
ahh must be the moatherboard then, my Shuttle AN35N Unltra 400, same chipset as yours defaulted it to 1.8GHz 13.5*133 like i said above, i figured most did that

and from that newegg page "Operating Frequency: 1.8GHz" so i could be right, you most likely are running in async mode, or y ou have the best pc2100 ever, see if you can run it at a higher multyplier and get even more out of the chip, as long as you are keeping the ram locked down it shoudl work

Uh... When implementing Dual Channel with two slower modules you are ALWAYS running async mode.

I honestly don't understand why my brother (Ichinisan) EVER thought that the FSB was supposed to be clocked at 400MHz and the DDR at 200MHz or why no one corrected OS...

Originally posted by: OS
You need DDR400 ram to run 400 FSB (200 mhz double clocked) in sync. How many sticks of ram you have, have almost nothing to do with the bus speed you want to run.[/q

It's clear that he does not want to run them "in sync" but specifically in asynchronous dual-channel mode. How many sticks of ram you have is very important when using dual channel mode... Otherwise, he may as well leave the FSB at 133/266! It's the reason dual-channel was created. Two DDR266 sticks do exceed the bandwidth requirements of a DDR400 bus and will provide the benefits of a 400MHz FSB to a 400FSB CPU. Believe it or not, dual-channel is not exclusively for the few nForce 1 & 2 IGP boards that need more graphics bandwidth.

Originally posted by: OS

Originally posted by: Ichinisan
That's the point of dual channel. Two sticks running together to double the thoroughput. I should be able to set the processor at 400MHZ FSB

You go ahead and keep thinking that, while trying to run your PC2100 at 400 MHZ FSB.

You know that phrase about watching the dog chase it's tail?

He's not trying to run DDR266@400. He's simply confused and thinking that the FSB is really 400MHz and that it takes DDR400 or two DDR200+ sticks in dual channel mode to meet the FSB's bandwidth requirements. He's wrong about the FSB, right about the requirements.

 

[GasX]

Originally posted by: big4x4

Originally posted by: Anubis
ahh must be the moatherboard then, my Shuttle AN35N Unltra 400, same chipset as yours defaulted it to 1.8GHz 13.5*133 like i said above, i figured most did that

and from that newegg page "Operating Frequency: 1.8GHz" so i could be right, you most likely are running in async mode, or y ou have the best pc2100 ever, see if you can run it at a higher multyplier and get even more out of the chip, as long as you are keeping the ram locked down it shoudl work

My shuttle board recognizes my mobile barton

Mine didn't until I futzed with the settings and somehow underclocked it to 600MHz at which point it recognized the chip. When I sorted it out and set it to 2000MHz, it stopped recognizing the chip...

 

[rbV5]

I'm not sure if my RAM is actually overclocked or not. It's probably running in asynchronous mode, allowing me to set the processor FSB higher than the memory is actually running. I'm not sure how that works or even why it's an option...?

Async mode kills the performance of Nforce platform. You need to run your mem at 100% in the bios to run in sync with the FSB and that ram has next to no chance of that happening. You really need some better ram to get that mobile barton to perform...it'll be worth it.