new member, have a question

[IKu]

hi, i'm new, and this question is probably pretty easy for you people to answer. I've been reading up on FSB and matching cpu with motherboard with RAM and have gotten 2 conflicting views I think because one is for AMD and one is for Intel. So i'm gonna ask you people:

ok, so synchronizing FSB of the cpu, motherboard, and memory will result in the best performance, right? but what's more important, effective FSB (FSB including quadpump? for intel or doublepump? for amd) or the true FSB? this question is easy to answer in terms of AMD because new amd motherboards only use DDR memory and effective FSB is 2x true FSB... so it doesn't really matter cuz it matches either way, but intel boards have an effective FSB of 4x the true FSB and now can use DDR RAM. so if i have a intel motherboard with 4x100 FSB, should i use ddr200 RAM because the true FSB matches or ddr400 so the effective FSB matches (given the motherboard supports ddr400)?
thanks!!

[IKu]

hmm... it says 1 reply, but how come i can't see it?

[reboot]

It may have been edited/deleted for content.
Running RAM synchronous with a fast CPU (266mhz, doubled) usually gives the best stability. Sometimes (depending on board) you can run ram faster, and get a nice increase in speed, but not if you're using "dual channel".
Actually running ram asynchronous can be faster than dual channel in most cases.
Anyhow, if your CPU is a 266mhz bus, get at least DDR2100 to run at 266mhz. If your cpu is a 333mhz bus, get at least DDR2700. In other words, get the RAM that matches the base CPU bus speed, or direct multiplier/divider of it. Your 400mhz Intel will perform best with DDR32000 (400mhz).

[IKu]

thanks for the reply! can you explain "dual channel" or perhaps point me to a place where it is explained?

[glc]

Jim - Intel is quad pumped and the ram is only double pumped - actually the "match" is DDR1600 which is obsolete.

If you don't plan on upgrading soon, the best way to go would be PC2100, but faster won't hurt, it will just cost more. Intel chipsets will run asynchronous with no problem.

[piasabird]

If you use dual channel memory you get only slightly faster memory performance. However, you have to add Memory in matched pairs to use the motherboard. This makes for an expensive motherboard also. Usually these motherboards can use more memory because they have more slots for the memory.
What I have seen for price is that it is cheaper to purchase 1 512 Meg DDR RAM Dimm than two 256 Meg DDR RAM Dimms. So this makes the computer even more expensive.

Whether you go with AMD or Intel is up to you. I suggest pricing the motherboard and CPU and cooler you will need for both AMD and Intel and then read some revues of hardware at:
www.anandtech.com
www.tomshardware.com
or possibly some other hardware review sites. A lot of people have been purchasing the Asus A7N8X lately.

Many Game fanatics prefer to use PC3200 memory with the better memory latency ratings. However, some perefer to use PC2700 which is DDR 333. DDR 400 sometimes is unstable and actually can slow down a motherboard because it may generate too much heat for the memory or just run unstable.

I would not use an Intel Dual Channel Memory motherboard unless you plan on a $175-$250 Motherboard. If you have to have High end top of the line gear then money is not the most important issue and you should go for Intel.

[reboot]

I keep forgetting about Intel's (quad) bit. Sorry.
Anyhow, to get the most out of it, get the fastest ram you can afford, and run it asynchronous...which means that if you do get DDR3200 @ 400mhz, you CAN run it asynchronous, and really get some speed from it.
There's the odd time that DDR3200@400mzh does not work well asynchronously, not sure about on this board though. PC2700 @ 333mhz would be plenty fast.

[IKu]

Originally posted by glc Jim - Intel is quad pumped and the ram is only double pumped - actually the "match" is DDR1600 which is obsolete. If you don't plan on upgrading soon, the best way to go would be PC2100, but faster won't hurt, it will just cost more. Intel chipsets will run asynchronous with no problem.

glc, did you mean pc1600 rather than ddr1600?

also, are you guys saying getting pc2700 or pc3200 running asynchronously will help in terms of speed? i thought the 400 mhz cpu bus would negate any possible gains pc2700 or even 2100 would give? sorry about my newbie questions, just trying to learn!

btw, i do have pc2100, i'm just looking at possible ways to make everything synchronous cuz i heard that's best, but if you guys say running asynchronous is fine, i'll stop worrying so much about that.

[simwiz2]

400 MHz bus has 3200 GB/s.

PC 2700 RAM has 2667 GB/s.

The FSB can use the bandwidth, but the RAM needs to be run in asyncronous mode.

[reboot]

The 400mhz CPU is a 100mhz bus, quad pumped (multiplied by 4).
You CAN run ram asynchronously, and get much more speed from the system.
Get the ram you can afford, and run it as fast as possible.
No point in buying DDR3200 (400mhz) and running it at 100.

[Cricket]

For RAM, you take the motherboard FSB (Front Side Bus) which is either 100MHz, 133MHz or 166MHz (200MHz coming soon), and then the DDR RAM takes the motherboard FSB and "doubles" it (not really doubling the speed, the data is read twice per clock cycle). So, 100MHz FSB uses PC1600 or DDR 200...133MHz FSB uses PC2100 or DDR 266...166MHz FSB uses PC2700 or DDR 333...200MHz FSB uses PC3200 or DDR 400.

The CPU internal bus speed also depends on the motherboard FSB. AMD CPU's use DDR technology to read data twice per clock cycle. On the 100MHz FSB you would use a 200MHz AMD CPU...on the 133MHz FSB you would use a 266MHz AMD CPU and on a 166MHz FSB you would use a 333MHz AMD CPU.

Intel CPU's use Quad Pumped Technology to read data four times per clock cycle. On the 100MHz FSB you would use a 400MHz P4...on the 133MHz FSB you would use a 533MHz P4 and on the 200MHz FSB you would use a 800MHz P4 (Intel skipped the 166MHz FSB - 666MHz P4's and went straight to the 200MHz FSB - 800MHz P4's).

Based on the above, you match the RAM and CPU to the motherboard bus speed for synchronous timing unless your motherboard is capable of using asynchronous timing...in other words, if your motherboard uses the 100MHz FSB, you would use a 200MHz or 400MHz CPU along with PC1600 or DDR200 RAM. If your motherboard is capable of running asynchronous timings, you could use a 100MHz CPU (200MHz or 400MHz) with 133MHz, 166MHz or 200MHz RAM running at their correct bus speed (PC2100/DDR266, PC2700/DDR333 or PC3200/DDR400 RAM).

Gee...I hope this post makes sense...it seems kinda confusing.

Cricket

[glc]

Even if you are going to run async, there's no real point in getting ram faster than the top speed the board supports unless you are also going to be FSB overclocking or possibly upgrading the motherboard soon anyway.

[mike breck]

I don't quite understand that Cricket. Do you mind explaining it all again in MORE detail...



Only joking - you explained it perfectly.

[Andrewxcav]

What is the FSB of the 2500+ Barton?
I was thinking of using my current board with the Nforce2, a 2500+ and then either 2700 or 3200 RAM, the 2700 is cheaper, but my board supports 2 sticks of 3200, so I am torn...

any suggestions?

[IKu]

way to try to jack my thread
isn't the nforce2 a chipset? can you just change a chipset like that and keep the board?

also, a side question about overclocking, when you change the fsb (external clock?), do you also change the fsb of the memory?

[Andrewxcav]

no, the chipset is soldered on, godo question though

when you change hte FSB, unless otherwise stated in your bios with some of the newer ones, you are changing hte FSB on the CPU, RAM, and expansion slots.

new BIOS's may let you change the ratio for FSB/RAM/AGP

[IKu]

oohh... should have checked your sig, i thought you were getting the chipset and putting it on your current board... which already has it.

ok, so glc said, "there's no real point in getting ram faster than the top speed the board supports unless you are also going to be FSB overclocking or possibly upgrading the motherboard soon anyway."

why get faster ram when FSB overclocking? won't it overclock it anyway?

[Cricket]

Originally posted by Andrewxcav What is the FSB of the 2500+ Barton?

Don't the AMD Barton's use the 166MHz motherboard FSB to get the 333MHz internal CPU bus speed?

Cricket

[Andrewxcav]

That's my understanding, but I read about 400mhz

[Cricket]

Originally posted by Andrewxcav That's my understanding, but I read about 400mhz

I think that's only for the new 3200+ Barton.

Cricket

[Andrewxcav]

ah, its about darn time AMD gets their FSB up, now its on par with intels, minus that quad pumping mumbo jumbo

[Floppyman]

Yep, now it's 200mhz DDR on the new AMD's and 200mhz QDR on the new P4's. I wonder if AMD will ever go QDR?

[mike breck]

As the MHz and FSB war continues, you've got to ask yourself, what applications actually need this sort of speed?

It's like using a Mainframe for MS Works or Mine sweeper.

Or a Ferrari to do the shopping at the local supermarket.

As far as programming is concerned, I think the current power available from CPUs, video cards, and Ram almost encourages sloppy design and development.

[Andrewxcav]

its true, I remember going on AOL with a 33mhz cpu, now the program drags down p4's, simply bvecause it doesnt have to be efficient anymore

[glc]

why get faster ram when FSB overclocking? won't it overclock it anyway?

If you are going to be FSB overclocking, yes, the ram will follow if its bus is ratio based, so you need faster ram so it doesn't poop out.

[sleepypost]

currently i am UNDERclocking my RAM. (333 mhz fsb, 400 mhz DDR)