PC2700 Ram Bandwidth Int 2500 mb/s Sisoft Sandra on dual channel memory?

PC2700 Ram Bandwidth Int 2500 mb/s Sisoft Sandra on dual channel memory?(HELP plz)

Good evening ppl,

I know this question may have been asked, but should not I get higher benchies with dual channel memory controller of an Nforce 2 chipset?

My setup is as such:

A7N8X Deluxe revision 2.0
2 sticks of 256 meg of DDR333 and 1 stick of 512 meg of DDR400.
Bank one(slot 1 and 2) contains the two sticks of 256 and bank 2(slot 3) contains the last stick of 512 meg of ram.

I have tested the board with only the two stick of ram (256 meg each) in slot 1 and 3 as well as in slot 2 and 3 but the benchmark does not improve.

What gives? Cpu is AMD XP 2100+ running at 166 x 13 and the memory is running at 166 mhz as well.

My memory timings are 6-2-2-2-2.

Is this board bad? I have upgraded bios to 1.6 as well as installed the latest Nforce 2 all in one driver set.


To add to this, my Asus A7M266D with one cpu at 152x15 does 2400 mb/s Int and with two cpu/s does 2000 mb/s so I know that the dual channel setup is not functioning on the A7N8X Deluxe.

As always, I'd be immensely gratefull.

Ok I admit one thing I have not tried is running a single stick of ram.
This idea just popped in my head, since with a dual 2700 setup 3000 meg/sec is expected so 2500 meg/sec is very close.

I will update u if the benchmark varies with one stick of ram.

Ok with one stick of DDR400 running at 200 mhz I am getting 2900++ meg/sec in Sisoft Sandra memory benchmark.

That tells me that dual channel is not working on this motherboard.

Any advise at all? There is no function in BIOS to enable or to disable dual channel memory, but when the system boots u can see if its working or not.

I have tried like I said with only 2 stick, one in slot 1 and the other in slot 3 as well as the same two sticks, one in slot 2 and the other in slot 3.

It has posted with both configs as dual channel memory, but the benchmark is low.

Please help if you know the answer, I am ready to contact Asus and see if they can offer anything.

Thanks again

Ok I just spoke to Asus Tech support and they advised that there is a possibility that the memory is not matched for dual channel.
I have generic sticks of 256 meg DDR333 (I think samsung) so it may not have been tested to work in dual channel configurations.

Is anyone familiar with this kind of issue? I mean does that make sense at all?

I am prolly gonna order some high performace DDR400 256 meg sticks from New Egg but it would be great if the experts here could shed some light on this.

Thank you again.

Karifan

2500mb/sec is spot on for 166mhz. amd machine dont react the same as p4 machines do to dual channel ram - you wont see double the bandwidth infact you will be lucky to se a 15% improvement. Also, sandra has never reported dual channel bandwidth correctly for amd machines.


here's an example:

pc2700 is designed to run at 166mhz fsb. the maximum bandwidth for pc2700 is 2.7ghz (which is how it gets it's name - pc2700) concidering that the board will typically around 92% efficiant depending on the settings and ram, that gives you a ball-park figure of around 2484mb/sec, which is almost exactly what you get at 166mhz fsb.

those benchmarks seem spot on to me.

You are dead on as far as efficiency goes james.miller.
Sisoft Sandra reports a 94% to 95% efficiency, but I have been hearing reports of Nforce 2 Athlon boards specifically the Nforce 2 board showing 3000 + meg/sec in ddr 333 mhz mode.

And with DDR 400 it should be around 3500-3700 mb/s.

There is a review at Toms hardware of the Nforce 2 Asus A7N8X Deluxe as well as on anandtech.com and both reviews show high benchies with no overclocking.

Are there any better programs that show dual channel mode benchmarks correctly? PC Mark maybe or other?

Also Sisoft Sandra does not like the setup of the Asus A7N8X and does not report correct fan speed or vcore or motherboard temp.
And does not show any cpu temp at all.

Could it be that Sisoft Sandra is corrupt? I have tried sever installs of the latest version of Sandra.

Thank you,

ddr400 is pc3200. 3.2gb is the most you will ever get with an amd machine at 200mhz fsb. It's the cpu itself that is the culprit, not the board or ram.

the problem is that the amd's fsb is only double pumped, meaning that the cpu's memory interface runs at 2xfsb. At 166mhz fsb for example, it will be 166x2=333mhz. Thats exactly the same as the bandwidth available from a single stick of pc2700 (ddr333 - which runs at 166mhz x2). There lies the problem. if the cpu can only process the data as fast as a single stick of ddr can send it, then you will never get above the rated performance of a single stick, wether you use single, dual or quad channel (if there was such a thing).


Now, look at the intel p4. Their memory interface is quad pumped, meaing that they run at 4xfsb (100x4=400, 133x4=533 and 200x4=800mhz). With a 2.4c running at 200mhz fsb quad pumped, the cpu can process much more information from the ram. That is why dual channel is that much more effective with p4's - becuase the cpu isnt the bottleneck like amd cpus are.


even at 220 mhz fsb, i can only manage around 3.3gb bandwidth on my abit NF7-S v2

Im trying to figure all this stuff out as well guys since Im new to all this...my cpu runs @ 400 but I can only get the RAM to run @ 200. It won't post at all when set to 200% (400mhz) and there is no reason for that as far as I can tell. Now my board always runs in dual channel, but I specifically bought a matched pair (installed in slots 1 and 3) and that might be why it automaticlly sets it in dual channel..I think (I'm not positive) they have to be matched and not 2 generic sticks from possibly 2 different manufactured batches..its weird, Im seeing a lot of problems with this motherboard in the forums and I really dont have any issues other than my ram not running as fast as it should, but then again, you're dealing with a guy used to a P2 400mhz system 2 weeks ago, Im not even sure what kind of insane speeds I should be expecting I guess...as far as Im concerned its WAY faster than what I had, XP Pro install from fresh format in 10 minutes flat, no lie, installed 11GB of games in 55 minutes my old crummy 24x cd-rom....that took like 4 hrs before...

its ddr ram.

ddr stands for "Double Data Rate". basically for every piece of information sd-ram can process, ddr can do it twice. Therfore, ddr's theoretical speed is double the fsb (whereas sd-rams speed is equal to the fsb)

so:
ddr266 really runs at 133mhz fsb x2.
ddr333 really runs at 166mhz fsb x2.
ddr400 really runs at 200mhz fsb x2.

So basically dual channel in an Athlon configuration really yields no performace results? That Sucks.

Why are they selling us this crap then? lol
prolly cause we don't know until we try.

I am seriously contemplating returning this board and getting a P4 800 mhz board and running it in dual channel. Or wait an Opteron would prolly crush the P4, like a dual Opteron 240, right?

This is insane how systems become obsolete as soon as u buy the hardware. I think I am gonna start making my own hardware soon, lol

Karifan said:

So basically dual channel in an Athlon configuration really yields no performace results? That Sucks.

Why are they selling us this crap then? lol
prolly cause we don't know until we try.

I am seriously contemplating returning this board and getting a P4 800 mhz board and running it in dual channel. Or wait an Opteron would prolly crush the P4, like a dual Opteron 240, right?

This is insane how systems become obsolete as soon as u buy the hardware. I think I am gonna start making my own hardware soon, lol

Click to expand...

its not obsolete in the slightest lol. what you have there is the best bang-for-buck you will get for a long time. my rig will outperform p4 2.8c's at a fraction of the price. They are no top-performer - that's certain, but what can you expect for the price?