single channel versus dual channel memory setup

[John Doe]

Since I put some new memory modules in the wrong colored slots, I figured I
may as well test them before switching them for dual channel mode, for what
it's worth.

System:
MSI K7N2 Delta2-LSR (MS-6570E-030) mainboard up to 400MHz DDR support
Athlon XP 2400+ 2.0GHz CPU (133 MHz FSB)
two 512MB DDR400 PC3200 CL 2.5 (133 MHz FSB)
generic nVidia TNT 2 video card
Windows XP SP1a

WinRar
.... KB/s, single - 250, dual - 265
Sandra
....CPU arithmetic, single - 11,381, dual - 11,368
....CPU multimedia, single - 38,646, dual - 38,688
....memory bandwidth, single - 3,839, dual - 4,012
....filesystem benchmark, single - 38,352, dual - 38,300

 

[Conor]

Since I put some new memory modules in the wrong colored slots, I figured I
may as well test them before switching them for dual channel mode, for what
it's worth.

System:
MSI K7N2 Delta2-LSR (MS-6570E-030) mainboard up to 400MHz DDR support
Athlon XP 2400+ 2.0GHz CPU (133 MHz FSB)
two 512MB DDR400 PC3200 CL 2.5 (133 MHz FSB)
generic nVidia TNT 2 video card
Windows XP SP1a

WinRar
... KB/s, single - 250, dual - 265
Sandra
...CPU arithmetic, single - 11,381, dual - 11,368
...CPU multimedia, single - 38,646, dual - 38,688
...memory bandwidth, single - 3,839, dual - 4,012
...filesystem benchmark, single - 38,352, dual - 38,300

THe only thing worth testing is the memory bandwidth. Oh, and you need
to test it a few times to get a proper average.

 

[cowboyz]

Since I put some new memory modules in the wrong colored slots, I figured I
may as well test them before switching them for dual channel mode, for what
it's worth.

System:
MSI K7N2 Delta2-LSR (MS-6570E-030) mainboard up to 400MHz DDR support
Athlon XP 2400+ 2.0GHz CPU (133 MHz FSB)
two 512MB DDR400 PC3200 CL 2.5 (133 MHz FSB)
generic nVidia TNT 2 video card
Windows XP SP1a

WinRar
... KB/s, single - 250, dual - 265
Sandra
...CPU arithmetic, single - 11,381, dual - 11,368
...CPU multimedia, single - 38,646, dual - 38,688
...memory bandwidth, single - 3,839, dual - 4,012
...filesystem benchmark, single - 38,352, dual - 38,300

I noticed the same. Dual channel ram is overrated. I changed my soltek
DRV board for a FRN board to get dual channel and didn't notice the
difference. I also wanted the extra USB ports so it wasn't a complete waste
but disappointing.

 

[WayneM]

There have been several articles recently on dual channel memory. It is
basically a marketing ploy and the most you can expect is about a 5%
increase in speed. I guess it's worth it for some gamers trying to squeeze
every last bit of speed out of their machine.

It's definitely not worth it if you have to pay a premium for a "kit" of
supposedly matched sticks.

Wayne

 

[David Maynard]

I noticed the same. Dual channel ram is overrated. I changed my soltek
DRV board for a FRN board to get dual channel and didn't notice the
difference. I also wanted the extra USB ports so it wasn't a complete waste
but disappointing.

It depends on how it's being used. On an XP system if you're running 1:1
then the memory is already the same speed as the FSB so 'doubling'
(euphemistically speaking) the potential memory speed will have little
effect on CPU and memory benchmarks because the FSB can be served to almost
full capacity (except for some latency and bank overlap timings) by a
single stick, as your benchmarks show.

An interesting effect of that is that dual channel PC2100 will bench
roughly the same as dual channel PC3200 since the PC2100's lower individual
stick bandwidth is enhanced, as one would expect, by operating dual channel
while half the available PC3200 bandwidth is simply unused (bottlenecked at
the FSB).

The increased memory bandwidth *at the memory* (not the FSB) can help,
however, when there's other memory activity to service past simply the FSB;
as in AGP, on-board video, massive hard drive access, gigabit LAN, etc. (in
conjunction with heavy CPU load).

On a P4 system the situation is entirely different as the FSB is twice as
high as in XP systems and really does use the dual channel's higher
bandwidth. e.g. an effective 800Mhz FSB with 400Mhz memory.

 

[John Doe]

[dual channel mode] definitely not worth it if you have to pay a
premium for a "kit" of supposedly matched sticks.

If I were concerned about matching memory, I would just look for sticks
from the same lot. I'm not saying that's necessary, it's just the way I
would do it. Have fun.