Anybody else find Dual-Channel Memory not all it's cracked up to be?

[MichaelD]

Hi all. I'm running an Epox 8RDA+ with two, 512mb sticks of Corsair XMS3200. I'm running at 200MHz FSB, CAS2.5, 6-3-3, in single channel mode.

I tried doing it dual channel. The performance increase in synthetic memory scores like SANDRA and PCMark2002 was very minimal at best, and games were choppy and crashed sometimes.

Going back to single channel and all was well again.

What's the hype, there? I don't get it!

Thinking about moving from my heavily OCed XP2100, to a Barton with it's native 166FSB and running dual channel at 166MHz.

Any ideas on that?

 

[Jgtdragon]

Mine is working fine. Some dual channel motherboard is picky on the ram.

 

[Megatomic]

Aside from running a Barton at it's native 166MHz FSB that's exactly what I have done. See my rig (in the sig). I have a 2100+ Tbred B that I run as a 2700+ at 166MHz FSB with 1GB of PC2700 running at 100% in dual channel. My voltages are stock for Vdimm and almost stock for Vcore (1.65V) so my chip runs cool and I can use a quiet fan as a result.

My overall experience at this point is that my computer is intensely powerful and was very inexpensive. I am quite pleased with my system as a result. Gaming? It's great, I could use a little more GPU power (I'd love to get a FX 5900 Ultra) but my Ti 4800SE is good enough for now. And office apps? Office2K is loving it. Diskeeper XP too. Photoshop has never been this smooth for me either. As a matter of fact, I don't have any apps that slow my system down to the point that I feel like upgrading when I run them.

MichaelD, I think you'd be very happy if you followed your suggestion. The extra cache will make your system even more fluid than my own which is saying a lot IMHO. Good luck, sir.

 

[Le Québécois]

Had the same problem...but in the end it was one of my memory stick who was defect...have you tested them?

 

[Megatomic]

Oh and about DCDDR not being all it's supposed to be: we just don't use our systems in a fashion that would benefit from the bandwidth. I hearken back to the second review of the nForce2 chipset that Anand did. Remember the Spec benchmarks? You'd love your DCDDR if you ran scientic simulations and other similar types of software I think. And for me, I don't use the bandwidth either but I just love knowing that I have it if I ever need it. Plus I like "bells and whistles".

 

[MichaelD]

Thanks guys. I have ran Memtest86 on both sticks at their rated 166MHz and they both pass. Memtest86 will not get more than halfway thru on either stick while they are at 200MHz. I verified that here at AT in another thread.

Megatomic

Are you running the stock mulitplier on that XP2100? So, you're at 13x166 @ default voltage, right? What memory timings are you using? Thakns.

 

[John]

I run a pair of Geil 512MB ultra platinum PC3500 modules @ 200MHz 2-3-3-6 on my NF7-S v1.2

Sandra 03 - 3049/2918

 

[MichaelD]

Originally posted by: John
I run a pair of Geil 512MB ultra platinum PC3500 modules @ 200MHz 2-3-3-6 on my NF7-S v1.2

Sandra 03 - 3049/2918

Hi John, is that in dual-channel? Nice scores, BTW.

 

[Megatomic]

Yep, I use the default CPU multiplier (13x) and close to default voltage. I have to run the CPU at 1.65V to get complete stability (24+ hours of Prime95). I can run at 1.625V but Prime95 fails after a few hours so that's no good. Default voltage for my CPU is 1.60V btw...

My memory runs at 5-2-2-2.0 when set to 100%. The default Vdimm at default which is 2.63V on my 8RDA+.

I don't use Sisoft Sandra for my memory scores, I use Aida32 where I get 2508MB/s Read and 1030MB/s Write.

 

[IamG]

Has it ever been confirmed (other than by the manufacturer) that there so called "dual channel" RAM has any benifit at all over two sticks of plain-jane RAM?

I always thought it was just a marketing ploy to raise the cost by $25 per stick.

 

[dguy6789]

Dual channel is a great feature, it can give you double the memory bandwith that your system is running on. But your cpu fsb will only use memory equal to it in fsb, so an amd athlon xp 3200 will use 400 mhz of the "800" total of DC pc3200. but a 800 mhz fsb p4 will use all of it, notice the sisandra scores when the cpu uses all of the available bandwith, quite fast. But the spare memory speed will be useful for multi tasking, and i imagine integrated graphics would love thay kind of bandwith.

 

[MercenaryForHire]

Originally posted by: dguy6789
Dual channel is a great feature, it can give you double the memory bandwith that your system is running on. But your cpu fsb will only use memory equal to it in fsb, so an amd athlon xp 3200 will use 400 mhz of the "800" total of DC pc3200. but a 800 mhz fsb p4 will use all of it, notice the sisandra scores when the cpu uses all of the available bandwith, quite fast. But the spare memory speed will be useful for multi tasking, and i imagine integrated graphics would love thay kind of bandwith.

/n00bslap

Double channel memory does not double the MHz speed. It doubles the available bandwidth.

But yes, it's practically a requirement when using the nForce2's IGP. Performance takes a significant hit otherwise.

- M4H

 

[MistaTastyCakes]

Dual channel RAM doesn't give big increases in every day use or games, but it does help with A/V encoding and such.

For most users, it's not a big deal, but it does give the edge with encoding, even if not shown very much on artificial benchmarks.

 

[MichaelD]

Originally posted by: Megatomic
Yep, I use the default CPU multiplier (13x) and close to default voltage. I have to run the CPU at 1.65V to get complete stability (24+ hours of Prime95). I can run at 1.625V but Prime95 fails after a few hours so that's no good. Default voltage for my CPU is 1.60V btw...

My memory runs at 5-2-2-2.0 when set to 100%. The default Vdimm at default which is 2.63V on my 8RDA+.

I don't use Sisoft Sandra for my memory scores, I use Aida32 where I get 2508MB/s Read and 1030MB/s Write.

Thanks bud. I may mess around some more w/dual channel this weekend. Being that I'm mostly a gamer, that big FSB pipe (200MHz) helps out a bit.

My particular CPU seems to need 1.700v in order to run at 2100MHz. I've tried 1.675v, but P95 fails almost immediately. With 1.700v, I can run it for 48 hours (and I have) while doing things like surfing and emailing simultaneously.

I need to check out Anand's review of the Barton to see if that $95 Newegg deal is worth doing.

 

[RaynorWolfcastle]

I've got a mini-comparison in the making, I should be done with it in an hour or 2. My hardware is very similar to yours

 

[MichaelD]

Originally posted by: RaynorWolfcastle
I've got a mini-comparison in the making, I should be done with it in an hour or 2. My hardware is very similar to yours

Excellent! I will check it tonight, as I"m getting ready to leave for work. Thanks!

 

[MercenaryForHire]

Originally posted by: MichaelD

Originally posted by: Megatomic
Yep, I use the default CPU multiplier (13x) and close to default voltage. I have to run the CPU at 1.65V to get complete stability (24+ hours of Prime95). I can run at 1.625V but Prime95 fails after a few hours so that's no good. Default voltage for my CPU is 1.60V btw...

My memory runs at 5-2-2-2.0 when set to 100%. The default Vdimm at default which is 2.63V on my 8RDA+.

I don't use Sisoft Sandra for my memory scores, I use Aida32 where I get 2508MB/s Read and 1030MB/s Write.

Thanks bud. I may mess around some more w/dual channel this weekend. Being that I'm mostly a gamer, that big FSB pipe (200MHz) helps out a bit.

My particular CPU seems to need 1.700v in order to run at 2100MHz. I've tried 1.675v, but P95 fails almost immediately. With 1.700v, I can run it for 48 hours (and I have) while doing things like surfing and emailing simultaneously.

I need to check out Anand's review of the Barton to see if that $95 Newegg deal is worth doing.

Barton $95 deal? I'm listening.

XP2500 I'm assuming. But with an SLK900 and a good 92mm, I don't think 200FSB would be tough.

- M4H

 

[MichaelD]

Originally posted by: MercenaryForHire

Originally posted by: MichaelD

Originally posted by: Megatomic
Yep, I use the default CPU multiplier (13x) and close to default voltage. I have to run the CPU at 1.65V to get complete stability (24+ hours of Prime95). I can run at 1.625V but Prime95 fails after a few hours so that's no good. Default voltage for my CPU is 1.60V btw...

My memory runs at 5-2-2-2.0 when set to 100%. The default Vdimm at default which is 2.63V on my 8RDA+.

I don't use Sisoft Sandra for my memory scores, I use Aida32 where I get 2508MB/s Read and 1030MB/s Write.

Thanks bud. I may mess around some more w/dual channel this weekend. Being that I'm mostly a gamer, that big FSB pipe (200MHz) helps out a bit.

My particular CPU seems to need 1.700v in order to run at 2100MHz. I've tried 1.675v, but P95 fails almost immediately. With 1.700v, I can run it for 48 hours (and I have) while doing things like surfing and emailing simultaneously.

I need to check out Anand's review of the Barton to see if that $95 Newegg deal is worth doing.

Barton $95 deal? I'm listening.

XP2500 I'm assuming. But with an SLK900 and a good 92mm, I don't think 200FSB would be tough.

- M4H

Yeah man!! Check hot deals!


Text


I just ordered one. Going to try this w/dual channel...might just leave it at 166MHz (default) if scores/performance are right.

 

[Megatomic]

HOLY CRAP!!! $96 for the retail Barton 2500+!! I hope this deal is still going on next Friday (payday). What are the chances of that?

If only I could get someone to buy one for me and I'll buy it from them on payday with a commission of course...

 

[RaynorWolfcastle]

The Mini-Review promised earlier

Enjoy

 

[glugglug]

Dual channel doesn't make much sense for Athlon, as the CPU has only a 64-bit bus, and is double pumped, not quad-pumped like the P4, so a single DIMM saturates it once the burst read starts.

It makes a much bigger difference on a P4 because of the quad-pumped FSB. Also makes a huge difference with Opteron since the FSB is 128 bits wide (in fact its required on most if not all boards for it).

 

[RaynorWolfcastle]

Originally posted by: glugglug
Dual channel doesn't make much sense for Athlon, as the CPU has only a 64-bit bus, and is double pumped, not quad-pumped like the P4, so a single DIMM saturates it once the burst read starts.

It makes a much bigger difference on a P4 because of the quad-pumped FSB. Also makes a huge difference with Opteron since the FSB is 128 bits wide (in fact its required on most if not all boards for it).

You're absolutely right, except that with dual channels AMD users can:
A) Instead of buying stick of PC3200 you can buy 2 sticks of PC2100 and run your FSB as high as you want while running everything within spec (saves money)
B) nForce2 boards use data prefecthing. This prefetching requires bandwidth, so using a dual channel set up gives it that extra bandwidth while keeping the CPU in sync with the RAM (slightly better performance)

 

[MichaelD]

RaynorWolfCastle, nice review. That's a lot of work, I know; I've done something similar before.

I'm still not really sure that dual-channel is for me, as I can run my 1GB of memory, in single channel at 200MHz and keep all that fat pipe. *shrug* I guess I'll do some more experimenting. *puts on mad scientist hat* Mwuahahah!

 

[MercenaryForHire]

Originally posted by: MichaelD

Originally posted by: MercenaryForHire

Originally posted by: MichaelD

Originally posted by: Megatomic
Yep, I use the default CPU multiplier (13x) and close to default voltage. I have to run the CPU at 1.65V to get complete stability (24+ hours of Prime95). I can run at 1.625V but Prime95 fails after a few hours so that's no good. Default voltage for my CPU is 1.60V btw...

My memory runs at 5-2-2-2.0 when set to 100%. The default Vdimm at default which is 2.63V on my 8RDA+.

I don't use Sisoft Sandra for my memory scores, I use Aida32 where I get 2508MB/s Read and 1030MB/s Write.

Thanks bud. I may mess around some more w/dual channel this weekend. Being that I'm mostly a gamer, that big FSB pipe (200MHz) helps out a bit.

My particular CPU seems to need 1.700v in order to run at 2100MHz. I've tried 1.675v, but P95 fails almost immediately. With 1.700v, I can run it for 48 hours (and I have) while doing things like surfing and emailing simultaneously.

I need to check out Anand's review of the Barton to see if that $95 Newegg deal is worth doing.

Barton $95 deal? I'm listening.

XP2500 I'm assuming. But with an SLK900 and a good 92mm, I don't think 200FSB would be tough.

- M4H

Yeah man!! Check hot deals!


Text


I just ordered one. Going to try this w/dual channel...might just leave it at 166MHz (default) if scores/performance are right.

God dammit, newegg again. They hate Canadians. Someone buy a spare and sell it to me for +10%.

- M4H

 

[DAPUNISHER]

Originally posted by: glugglug
Dual channel doesn't make much sense for Athlon, as the CPU has only a 64-bit bus, and is double pumped, not quad-pumped like the P4, so a single DIMM saturates it once the burst read starts.

Where the DC-DDR shows it's stuff is with IGP as several have mentioned and it makes perfect sense. If you look at Anand's review you can see how using both 64bit controllers and increasing the ram speed continues to boost it's performance and even without IGP core overclocking using coolbits I've seen the performance continue to improve with bandwidth when running DC-DDR in synch mode to help reduce the latency demonstrating it's taking whatever the CPU doesn't need very greedily. Even with the SPP if you can run DC-DDR 200mhz synch there's a nice little boost that makes it worthwhile IMO. Not to mention if you decide to go with the Intel DC-DDR solutions later because of the excellent performance they are showing then you already have a couple sticks of 3200DDR or higher to slap in it instead of having to buy another stick at that time