About DUAL channel

[hishamelprince]

Which is better:
1) single 1GB chip in a single slot
2) 2x512MB in 2 slots operates in dual channel mode
3) 4x256MB in 4 slots each two of them works in dual channel mode
Thanks

 

[hishamelprince]

Please guys someone answer me

 

[Cheex]

Well I have 2x512MB right now (dual channel) but i'll be trading that out for a single 1GB stick.
That way I can add another 1GB stick to dual channel that when I need more memory (2GB).

Dual core processors aren't really memory bandwidth limited. They more rely on the FSB for "communication". Dual channel show more of a benefit for single core processors.

I would suggest the single 1GB stick if you run a dual core cpu. Then upgrade and get a matching stick later.
What cpu do you have?

 

[hishamelprince]

Thanks
i have a pentuim 4 cpu single core with 2.8GHz /1MB cache/533FSB

 

[Peter]

Use all channels, each with as few DIMMs and chips as you can. One DIMM better than two, single-sided better than double-sided.

Cheex's FSB comment applies to Intel processors only - AMD x64 processors have the RAM controller integrated, no bottlenecks here.

Your 533FSB Intel has a theoretical maximum throughput of 4200 MB/s, and thus is bottlenecked by RAM if it's less than dual-channel PC2100.

 

[Cheex]

Well in that case....

Get 2x512MB DDR2-533 RAM.
At 533 its slower than the others but it will run 1:1 with your CPU which is the best ratio. It gives the best RAM performance.
Plus it will be cheaper too...

 

[hishamelprince]

i forgot to tell you that my motherboard supports only DDR1

 

[Peter]

Originally posted by: Cheex
Well in that case....

Get 2x512MB DDR2-533 RAM.
At 533 its slower than the others but it will run 1:1 with your CPU which is the best ratio. It gives the best RAM performance.

No it doesn't. DDR2-533 actually runs at 266 MHz, while Intel's "FSB533" actually is 133 MHz QDR.

As I said above, dual-channel is a must, and anything DDR-266 (aka PC2100) or above is good enough. DDR-266 would give you the "perfect" clock ratio of 1:1, but you should nonetheless get mainstream PC3200 DIMMs.

 

[hishamelprince]

Originally posted by: Peter
No it doesn't. DDR2-533 actually runs at 266 MHz, while Intel's "FSB533" actually is 133 MHz QDR.

As I said above, dual-channel is a must, and anything DDR-266 (aka PC2100) or above is good enough. DDR-266 would give you the "perfect" clock ratio of 1:1, but you should nonetheless get mainstream PC3200 DIMMs.

Then you saying that i go with the 2x515MB DDR1-400?
or the 4x256MB ?
Thanks

 

[Cheex]

Oops. I got a few wires crossed. My bad.


Get the 2x512MB DDR-400.

 

[hishamelprince]

Ok one last question?
does the 2 chips have to be exactly the same in type, i mean from the same manufacturer ?
or just they have to be the same in the capacity and speed?
thanks

 

[AstroGuardian]

The two sticks MUST BE SAME MANUFACTURER AND SAME MODEL to obtain maksimum performance and STABILITY.
Pay attention to that fact

 

[Peter]

Well technically they have to use RAM chips of the same physical geometry, and they have to have /some/ common speed and timings.

Of course you're best off with an identical pair. Note that some manufacturers actually charge more for a twin pack than for two single units, although there is nothing "specially selected" or somesuch bull about the twin packs - it's just two units from the same production run.

 

[AstroGuardian]

Correct!

 

[Rottie]

2 sticks will have 1T command for a better performance than 2T with 4 sticks.

 

[f4phantom2500]

actually i remember reading a review for a p4 chipset (by via) that used single channel memory, which was compared to intel boards that used dual channel (this was back when the 800fsb p4's were out and about). if i recall correctly, the via chipset kept pace very well with the intel boards, despite its "limitation", of course they were using ddr400 ram. i mean, im pretty sure the intel boards did better in memory benchmarks and such, but in real world apps the via board kept pace very well. so, i doubt it matters with a 533fsb p4.

if it were me, i'd go 1gb in 1 slot or 2x512 in 2 slots, whichever's cheaper. since the dual channel won't really matter it wouldn't bother me that much, but it might you so if you care that much go with the 512's. also, assuming you have 4 dimms (since you asked 4x256), this way you can fairly easily upgrade to 2GB. might be cheaper to go the 512 route since a lot of people have 512mb ddr sticks that they don't use anymore (am2 and lga775 upgrades), might be able to pick some up for cheap from them.

 

[Peter]

It doesn't matter for many things because these tasks aren't using the memory too hard. In applications that do use RAM heavily, the P4 depends more on good RAM throughput than any other CPU type.

Give it dual channel if you can.