Adding extra memory to your PC can slow it down

[ayoub_ibrahim]

On the Athlon64 and Pentium4 i875 platforms, the more memory you add, the slower the memory performance. In the case of the Athlon64, the drop occurs with a drop to 1.6GB/s bandwidth, half its peak. It can transfer less data for the same amount of time. In the case of the Pentium4, the performance drop is supposed to be an increase in latency, but maintains the DDR400 bandwidth of 3.2GB/sec. It's top speed is the same, but has slower acceleration.

What we are saying is that adding extra memory can reduce system performance if it is unused. You won't believe me without the proof, so let's take a look at the benchmarks again when running additional RAM.

http://firingsquad.com/hardware/building_gaming_opteron_2003_Part2/page14.asp

[Brian R.]

"It's disappointing that despite the immense press coverage of the i875P and Athlon64 platforms, no one has stopped to evaluate the performance issues of greater than 4 banks of memory in a set of real-world tests. CacheMem and other synthetics cannot tell the story that a few real-world tests can show. This is particularly true because RAM is getting cheaper by the day, and it is not uncommon or difficult for users to buy more than a gig of RAM, expecting better performance. Moreover, it is particularly unfortunate that many motherboard manufacturers continue to advertise their boards with maximum memory capacity rather than maximum memory capacity at full speed. ASUS does provide documentation in their manual regarding the maximum recommended memory configuration at a given speed. We commend ASUS for their interest in keeping the customer informed about the strengths and weaknesses of their products."

I knew I likes ASUS boards for a reason...

[WyWyWyWy]

I dont understand
The Athlon64 board is dual-channel, right?
Using 3 modules of course can't be dual-channel, so it of course slows down by 1/2.

And on P4, higher latency is of course required due to synchronising.

So... what exactly does this artcile prove?

[J1NG]

Dunno, all I know is Opteron seems to be unaffected. And I'm happy with that!

Maybe Asus wrote a cheque...? Someone dating an Asus high up? Or maybe they just like Asus.

J1NG

[rylan]

The articles shows that Intel boards and their 4-6 dimm slots are all hype, because the huge latency makes it perform slower than the AMD system running at PC1600 speed. :P

[Nuno]

No, Athlon64 is single channel.
I wonder if this affects Nforce2 chipsets... I´ve got the single channel Asus A7NX-X and I may get another memory stick, having now 2x256Mb...

[The PIT]

Got to admit when running four sticks I didn't notice any slow down in real world apps. Quite often I do use a lot of memory though.

[Technoid]

Whew
For a moment I thought that some one was trying to resurect a PC Myth I thought dead and buried

Thankfully there was no wanna be necromaniac on the loose this time

[Taz]

Athlon 64 is single channel, Athlon 64 FX51 and Opteron are both dual channel

[rylan]

Thats also why the FX51 and Opteron require registered memory.... you won't have to reduce the speed or jack the latency up to compensate for skew and loading as you add modules.

[The PIT]

Debunked

http://www.lostcircuits.com/memory/2gb/

The above fits in with another article that I read sometime ago.