A7N8X Deluxe Dual Channel memory?

[Ric]

I just bought a second stick of RAM and installed per the manual such that
the 2 sticks are in the 2 rightmost slots (2 & 3, both blue). I did a SiSoft
Sandra memory bandwidth test and was underwhelmed by the ~1830 MB/s score.
Then I thought maybe there was a misprint in the manual and they meant that
one stick has to be in slot 1 (the leftmost, black one) to enable dual
channel. So I switched the stick from slot 3 to slot 1 and benchmarked
again. ~1730 MB/s. Is the advantage of dual channel really that meagre or is
there something else I need to do to activate it?

Thanks,
Ric

 

[Ben Pope]

I just bought a second stick of RAM and installed per the manual such
that the 2 sticks are in the 2 rightmost slots (2 & 3, both blue). I
did a SiSoft Sandra memory bandwidth test and was underwhelmed by the
~1830 MB/s score. Then I thought maybe there was a misprint in the
manual and they meant that one stick has to be in slot 1 (the
leftmost, black one) to enable dual channel. So I switched the stick
from slot 3 to slot 1 and benchmarked again. ~1730 MB/s. Is the
advantage of dual channel really that meagre or is there something
else I need to do to activate it?

Both of those setups are Dual Channel.

What speed you running your RAM at and is that Synch with the FSB?

I get 2431/2301 at 166MHz, which looks to me like you're running 133MHz.

My timings are 5-2-2-2.

Ben

 

[Doug Ramage]

Both of those setups are Dual Channel.

What speed you running your RAM at and is that Synch with the FSB?

I get 2431/2301 at 166MHz, which looks to me like you're running 133MHz.

My timings are 5-2-2-2.

Ben
--

Currently, Sandra states 2656/2537 at 180Mhz, running in sync with FSB.
IIRC, dual channel gives me about an extra 5%. Timings are 8-3-3-2.5.

 

[Ben Pope]

That sounds more reasonable. I don't know why my RAM is running so
slow. I noticed that in the first configuration above when I boot the
BIOS states "dual channel" on the bootup page (after the memory test)
but with the second configuration it says "single channel" so it does
look like the manual is correct.

The manual states (in a roundabout way), that you need a Dimm in slot 3, and
any other Dimm slot populated.

Both configurations you mentioned should be Dual Channel.

I'm running 166 with memory in sync with cpu. I installed the new
nvidia system utility and it confirms:

Front side bus: 334.091 MHz (DDR)
Memory bus: 334.091 MHz (DDR)
AGP bus: 66.818 MHz
CPU multiplier: 12.5x
CPU speed: 2088.068 (MHz) (I'm overclocking a 2100+)

T (RAS): 3 (currently, but I also tried other values like 7, 14 and
15 with no significant effect on performance, I'm not too clear on
what this value should be set at.)

Seems low. Try it at 7.

T (RCD): 2
T (RP): 2

What about Cas Latency?

So any ideas why I'm getting practically half the memory bandwidth
you guys are??? Do I have my timings all backwards or something? I do
notice my CPU goes to 100% during the SiSoft memory test. Is this
normal?

Probably.

Ben

 

[Ric]

The manual states (in a roundabout way), that you need a Dimm in slot
3, and any other Dimm slot populated.

Both configurations you mentioned should be Dual Channel.


Seems low. Try it at 7.

I did. Doesn't help.

What about Cas Latency?

TRAS is 3, everything else is 2.