DDR400 performance < 333?

[hjo3]

I'm about to upgrade to a motherboard that supports DDR400 (currently, all my systems that use DDR only work with 2100/266). I wanted to get some DDR400 memory for it. I was talking this over with a friend and he said that DDR333 is actually faster/performs-better than DDR400. This sounds wrong to me... can anyone confirm this? A link to some DDR benchmarks (comparing stuff from 266 to 466, esp.) would be greatly appreciated.
TIA

 

[brettjrob]

It depends on the platform, CPU, etc. Post some specs and then we'll be able to tell.

 

[Acanthus]

If you are running dual channel DDR, on a pentium 4. Then Dual DDR333 will be within 1-2% of ddr400 for most appz.

BUT if you are running an 800fsb pentium 4, then dual DDR400 really shines.

You dont need dual channel for an athlon, simple.

And VIA is banging out a new Intel chipset where SINGLE CHANNEL DDR400 keeps up with the duals! But its VIA

 

[hjo3]

But, all things equal, will 333 ever outperform 400?

Specs:
Barton 2500+, MSI KT4VL

 

[brettjrob]

If you're planning on running the Barton at stock speeds (1.83GHz @ 333MHz FSB), then PC2700/DDR333 would be your best bet since the prices of DDR400 are significantly higher right now. If you want to overclock it and run it at 400MHz FSB (very common practice for 2500+ users I've heard), you'll need the PC3200/DDR400. The only case in which DDR400 might be outperformed by DDR333 is if only the RAM is running at that frequency, while the CPU is still running at its regular (266 or 333) FSB. And in those cases, the only reason is because of the lower timings necessary on some RAM when you put the module at 400MHz FSB.

So for you, overclock = DDR400, no overclock = DDR333.

 

[hjo3]

Ahhh, okay, thanks a lot!

 

[Lonyo]

Originally posted by: hjo3
But, all things equal, will 333 ever outperform 400?

Specs:
Barton 2500+, MSI KT4VL

As said above, if your doing stock speeds, DDR333 will probably be the better option.

When AMD processors run with the RAM at the same speed as the front side bus, they have optimum performance.

If the processor has 166MHz FSB, then DDR333 (166x2) is the best option as it means the speeds are in sync. If you had DDR400 and ran it at its proper speed, it woul dbe 200MHz, higher than the 166MHz of the processors FSB, this can actually harm performance.

I would advise that you buy DDR400 RAM, as this can run at speeds of just 166MHz (333MHZ DDR) which is in sync with your processor. DDR400 will also probably allow for tighter timings (lower latency) at the DDR333 speeds.
DDR400 will also future proof you more, if you want to go for a Barton 3200+ (which has 200MHz FSB) or a P4 system with 200MHz FSB (800MHz Quad pumped)
Also, DDR400 will allow you to overclock your Barton possibly more than DDR333 would.

 

[jscott1226]

Which memory would you suggest for an xp 2400+?

 

[Acanthus]

if youre not running a 400fsb, pc2700 is always good especially with the dirt cheap prices its going for now, a gig is like $135 shipped at newegg for kingston valueram 2700.

 

[hjo3]

Originally posted by: Acanthus
if youre not running a 400fsb, pc2700 is always good especially with the dirt cheap prices its going for now, a gig is like $135 shipped at newegg for kingston valueram 2700.

Sounds great, but I can't find it... could you gimme a link? The cheapest 1 GB DDR333/PC2700 RAM I can find on Newegg is $165 for a Corsair kit.

 

[hjo3]

nm, got 512 DDR333 @ googlegear for $84 shipped 2-day

 

[zephyrprime]

All the early chipsets had bad performance with DDR400. It was actually worse than with DDR333 for reasons unknown to me. Just just Anand's own articles of the early chipsets.

It's not a problem anymore.

 

[Pezman]

Originally posted by: brettjrob
If you're planning on running the Barton at stock speeds (1.83GHz @ 333MHz FSB), then PC2700/DDR333 would be your best bet since the prices of DDR400 are significantly higher right now. If you want to overclock it and run it at 400MHz FSB (very common practice for 2500+ users I've heard), you'll need the PC3200/DDR400. The only case in which DDR400 might be outperformed by DDR333 is if only the RAM is running at that frequency, while the CPU is still running at its regular (266 or 333) FSB. And in those cases, the only reason is because of the lower timings necessary on some RAM when you put the module at 400MHz FSB.

So for you, overclock = DDR400, no overclock = DDR333.

Yup, that's what I use on my cpu/board combo. It works just fine!

 

[AgaBoogaBoo]

I didn't read the other posts but it might be lower because if you run it higher than the FSB, it might not be as efficient in transferring data... or something along the memory and FSB not being in sync