what does this mean?

[surfryde]

I have 512mb kingston hyper x pc3200, and when my computer posts, it says memory speed is 200mhz, single channel mode.<BR><BR>I know that 400 mhz ddr really runs at 200mhz but transfers data on both clock cycles, so in essence you have 400 mhz, but what does the single channel mean, and is that slowing my computer down compared to if I had 2 x 512mb sticks running in dual channel mode?<BR><BR>Thanks in advance

[Ginsu543]

I don't know too much about this, but theoretically dual channel is supposed to give you more bandwidth than single channel (thus higher performance). I've heard some very knowledgeable people here (such as Colin) say that running ram dual channel doesn't give a performance boost for Athlon XP cpus because these cpus don't require the higher bandwidth, unlike Pentium 4 cpus. However, when I was experimenting with my ram set up, I got higher memory benchmarks on Sandra running dual channel than single channel.<BR><BR>The only way to find out for sure is to get a second stick and try them out! <img src="i/expressions/face-icon-small-happy.gif" border="0">

[Avid6eek]

Dual channel memory is the same as running 2 harddrives in a RAID 0 setup. With dual channel, your have 2 memory modules. The system information that is stored in the RAM is split between the two different channels and goes to the two different memory modules. PC3200 has a peak bandwith of 3.2GB/second. Dual channel PC3200 has twice as much, 6.4GB/sec. Of course you will never actually be able to use all 6.4GB/sec of bandwith as the Athlon XP doesn't need that much. I'm sure that there are some instances though, when the Athlon does need more than only 3.2GB/sec.

[TranceJunkieXL]

Is your 512MB consisting of 2 x 256MB sticks? If it does, then you need to crack the manual to find out which 2 DIMMs they need to be installed in to enable the Dual channel (BAM! would know).

[Ginsu543]

Rithem, I think (from his other posts) surfryde has one 512 MB stick.

[surfryde]

yeah, I have one 512 stick, but for some reason my signature says I have two.

[surfryde]

I think for the A7N8X Deluxe i can get dual channel from memory sockets 1 and 3, or 2 and 3. For some reason it doesn't work when memory is in sockets 1 and 2?

[Avid6eek]

Dimms 1&2 are on the first memory channel, and Dimm 3 is on the 2nd memory channel.

[surfryde]

that makes sense. I'm curious, anyone know why there aren't 4 memory slots on DDR mobo's (i.e. 2 on one channel and 2 on the other channel)?

[Avid6eek]

That's a good questions, and it would really be nice if they had 4. Most of us with 512MB of RAM have 2x256 so we can run dual channel. In order to upgrade to a gig, we need to sell our RAM, and buy 2x512. Four memory Dimms would make things a lot easier.

[Avid6eek]

Then again, it's hard enough to get 2 memory modules that work right together....finding four would probably be impossible <img src="i/expressions/face-icon-small-smile.gif" border="0">

[surfryde]

Is it really that hard to find two that work good together? If I got another 512 of the same brand and number, shouldn't they work together fine?

[Avid6eek]

They should work together fine, but unless you specifically buy a twin pack, you can never know for sure. If you just buy two modules, they will most likely work together, but not at the same timings they are advertised to work at alone.

[Ginsu543]

<br><br><< <i>but for some reason my signature says I have two</i> >><br><br><BR><BR>Well then, why don't you update your sig to say that you only have one? <img src="i/expressions/face-icon-small-happy.gif" border="0"><BR><BR>I have two pairs of OCSystem 512MB PC3200 ram and they weren't a twin pack (I bought them before there was such a thing as a twin pack), but they seem to work fine upto their advertised speed of 400 MHz at 5-3-3-2.0 timings in dual channel mode. I do begin to get instability once I go higher than 200 MHz. If you are that paranoid about it, why don't you sell your stick on eBay and get yourself a twin pack? That way you'll know for sure that they work.

[TranceJunkieXL]

<br><br><< <i>Well then, why don't you update your sig to say that you only have one?</i> >><br><br> I thought there was a hint of sarcasm in what he said, but I let it pass. lol <img src="i/expressions/face-icon-small-smile.gif" border="0">

[Ginsu543]

Touche! <img src="i/expressions/face-icon-small-happy.gif" border="0"><BR><BR>But all in good fun, of course.

[Assimilator87]

Hey Ginsu, why don't you lower your timings a little? I'm sure it'd run at at least CL 4 since it's not even overclocked. According to PC Wizard 2003, my CL is 3.

[Avid6eek]

CAS 3 - Ouch<BR>CAS 4 - OMG

[Ginsu543]

I think we're a bit confused here, so let me try to clear up what we're trying to say. When we say ram timings, we're talking about four things:<BR><BR>(1) Cycle Time (Tras)<BR>(2) RAS Precharge<BR>(3) RAS to CAS Delay<BR>(4) CAS Latency<BR><BR>For all these values, lower is better. Right now, I have my ram set at 5-3-3-2 respectively. Now, assimilator, when you say I should lower my CL to 4 or 3, do you mean the Cycle Time (which I have set to 5) or the CAS Latency (which I have set to 2)? If you mean the Cycle Time, then I can't, because that is the lowest value I can set and still have a stable system at 400 MHz FSB DDR. Believe me, I've tried. Besides, I've never heard of anyone running their ram Cycle Time at 4 or 3 when running 400MHz. I myself have gotten it down to 3 when I had my FSB at 333MHz. But higher FSB gives more of a performance boost than lower Cycle Time, so I opted for the 400MHz even though the Cycle Time has to go up to 5. On the other hand, if you meant CAS Latency, then setting that at 3 or 4 would be counter-productive since that would make my rig even slower, not faster.

[Assimilator87]

Thanks for the info.<img src="i/expressions/face-icon-small-shocked.gif" border="0">