The Case of the Counterfeit CAS

[Boundless]

Buying RAM is an <expletive deleted> minefield.

So I have most of the components lined up for the next build
(an AM2+, details in footer). How hard could it be to pick out
some suitable DDR2/1066 RAM?

Not trivial, as it turns out, and not just because the tech
landscape has changed since my last build (DDR1/PC3200).

For example: "voltage" is now a buzzword spec, but no one
explains what it implies (max? recommended? required?).
Stock JEDEC calls for 1.8V. Do higher spec'd DIMMs run at 1.8?
Some buyers seem surprised when it does.

The scandal:
It appears that most "enthusiast" RAM is overclocked stock,
which SPDs as lower speed stuff, requires BIOS tweaks
(including RAM voltage), and may or may not then achieve
its claimed speed.

The 1066 stuff seems to be largely overclocked,
overpriced, overhyped DDR2/800.

The brands even admit the stuff SPDs at lower speeds.
Some rely on EPP to get the RAM to run at claimed
speed, but of course no AMD chipsets support EPP yet.

The comments on the various DIMMs on the Egg are
frankly appalling. And sure, some of these buyers are
pushing their RAM, but a huge number of complaints are
about RAM not delivering advertised performance.

This looks very much like the wild west days of shady
resellers re-marking CPU speeds. Few of the RAM brands
even bother to respond to the complaints on the Egg,
which lets the reader draw the conclusion that the
problems are real.

1066 has other issues, too, like only one stick/channel.

So I'm thinkin' I might as well buy some low latency 800.
But whose? None of the "brands" actually make RAM chips,
although at least one (Crucial) is the retail arm of a
foundry (Micron). Are any of the other brands similarly
aligned with Elpida, Hynix, Infineon, Qimonda or Samsung?

Even Crucial gets crucified in the Egg comments (for
their Ballistix enthusiast line). And their stock line
is not immune from problems. My present machine is using
stock Crucial, and I recently solved my random crashing
problem by backing off one notch from the stock SPD RAM timings.
________
Proposed system:
CPU: AMD Phenom X3 8650
Motherboard: ASUS M3A78-T (790GX/SB750)
OS: Windows XP32
RAM: 4GB (2x2 DIMMs) (and yes, only ~3GB will be useable)
Must be unregistered DDR2 240pin DIMM
Max of one per channel if PC8500/1066
Max of 2GB per slot.
Avoid ECC even though supported, due to IGP UMA
EPP, if present, is ignored.
I have the current QVL (and stock Crucial isn't on it yet).

[Boundless]

> The 1066 stuff seems to be largely overclocked,
> overpriced, overhyped DDR2/800.

Interestingly,
Crucial wants $86 for 2 sticks (4GB total) of "stock" CAS6 DDR2/800,
CT2KIT25664AA800
and
a whopping $230 for 2 sticks (4GB total) of "stock" CAS7 DDR2/1066.
CT2KIT25664AA1067

And by "stock" I mean 1.8V, no heat spreaders, and no timing claims other than CAS.
_________
It clearly is not cheap to make DDR2/1066 to JEDEC spec.
My guess is most brands don't. What they sell as 1066 isn't
any such thing.

[AussieFX]

I didn't think JEDEC had approved 1066 for DDR2.
As far as I'm aware all DDR2 ram that is rated above 800mhz is indeed just overclocked ram.
Micron seem to make the best ram with most pc8500/9200 being their D9GMH marked IC's.

You will not find anything that will run at 533mhz+ (1066) at 1.8v most will need 2.2v or more to reach those speeds.

Conclusion: 1066 and above is really enthusiast stuff and if you're not a semi experienced overclocker it is pretty much a given that people will run into trouble. Hence the bad reviews you have seen.
Just because a particular company has tested the sticks to run at X speed doesn't imply that it is guaranteed to run at that speed in your machine (when outside JEDEC specs) Once again this catches out a lot of inexperienced people. I have also noticed that some people need to boot the system with 1 stick at 1.8v before changing the voltage upwards to get the other sticks to boot. There can be a lot of fiddling to get it to work properly.

My advice: If you don't want the hassle get some nice Crucial Ballistix DDR2-800 4-4-4-12 and you won't notice the difference and if you really want 1066 you should be able to oc it and run at 5-5-5-18. with 2.2v+

[brit_spazman]

I didn't think JEDEC had approved 1066 for DDR2.
As far as I'm aware all DDR2 ram that is rated above 800mhz is indeed just overclocked ram.
Micron seem to make the best ram with most pc8500/9200 being their D9GMH marked IC's.

You will not find anything that will run at 533mhz+ (1066) at 1.8v most will need 2.2v or more to reach those speeds.

Conclusion: 1066 and above is really enthusiast stuff and if you're not a semi experienced overclocker it is pretty much a given that people will run into trouble. Hence the bad reviews you have seen.
Just because a particular company has tested the sticks to run at X speed doesn't imply that it is guaranteed to run at that speed in your machine (when outside JEDEC specs) Once again this catches out a lot of inexperienced people. I have also noticed that some people need to boot the system with 1 stick at 1.8v before changing the voltage upwards to get the other sticks to boot. There can be a lot of fiddling to get it to work properly.

My advice: If you don't want the hassle get some nice Crucial Ballistix DDR2-800 4-4-4-12 and you won't notice the difference and if you really want 1066 you should be able to oc it and run at 5-5-5-18. with 2.2v+

I made the mistake of buying 1066 ram, when I clock it that high my system wont post, I feel kinda cheated. I have yet to get my system to boot with the memory running @ 1066. 2.2V is a bit scary but does explain why my Dominator ram came with a fan!

Problem is now, that fan is being used as the exhaust for my water cooling

[Boundless]

AussieFX: > I didn't think JEDEC had approved 1066 for DDR2.

They did: SPECIALITY DDR2-1066 SDRAM (2007-11)

> You will not find anything that will run at 533mhz+ (1066) at 1.8v ...

I haven't exhaustively studied the spec, but it calls for 1.8v.
And yes, it could be that no 1066 out there is actually JEDEC compliant.

> Conclusion: 1066 and above is really enthusiast stuff and if you're
> not a semi experienced overclocker it is pretty much a given that
> people will run into trouble.

In addition to the OC-is-a-standard-feature issue, there is also
the problem of the double-secret one-stick-per-channel rule,
the usual assortment of people wondering where that 4th GB
went on Win32, plus rebate scams. Complaints abound.

> My advice: If you don't want the hassle get some nice Crucial
> Ballistix DDR2-800 4-4-4-12

I'm inclined to go with stock Crucial DDR800.
______
In part because I may yet get an X2 6400+ rather than
a slower-core ThreeNom or PhorNom.

[Boundless]

> Complaints abound.

Speaking of which, the Egg has user reviews, and allows
manufacturer comments. It's interesting to note which
brands take advantage of this feature, and which remain
silent, letting the rants sit there and fester.

The brand that seems the most responsive often can only
admit, "Yup, we lied. The SPD is lower."

Others have a limited command of English, and read like:
"All your RMA are belong to us."

Three don't seem to respond at all, including Crucial.
__________
And nobody talks about gold vs. tinned leads anymore.
Is everything gold now? Or is dissimilar metal still an issue?

[skrubol]

DDR3 is just as bad from what little experience I've had.
I built a Core2 Duo CAD machine (AMD gets eaten alive by Solidworks from what I've read,) with an MSI P35D3 Platinum mobo and 4GB of DDR3 1066. The damn thing would not boot with SPD timings and motherboard defaults. I had to go into the BIOS and tweak it.
I think the issue was a BIOS issue though, as it seemed to half go with the SPD info, and half go with the motherboard defaults (the chipset is only rated for 800MHz, even though it'll easily do 1066.)

[raceb4us]

Which would be more beneficial; 800MHz with lower latency or 1066MHz with higher latency on a Phenom platform?

[Boundless]

raceb4us: > Which would be more beneficial; 800MHz with lower
> latency or 1066MHz with higher latency on a Phenom platform?

It depends on whether your application mix is more sensitive to
latency or bandwidth, and how much you like BSODs.

Here's a circa 2004 test that PCstats did on
500 MHz 3-4-4-8 vs.
400 MHz 2-2-2-5
Memory Bandwidth vs. Latency Timings
In most of the tests, it was neck-and-neck.
Key findings:"...
Here in UT2003 we see the exact same results as the other
benchmarks have shown. If you're a gamer you're better off
having your memory run a bit slower if that means you can
use faster timings.
...
From the updated results shown above, AMD K8 processors
are clearly much more sensitive to lower latency DDR RAM,
and justifiably prefer it. ...

Usually the lower MHz RAM (with the tighter timings) is also going to be
cheaper, and probably more reliable, because it isn't on the bleeding edge.
__________
I'm planning on DDR2/800 for my 790GX build.

[raceb4us]

Boundless, I agree. thx

[muziqaz]

such a shame, that phenom 1066 support kind of goes to waste

[Boundless]

muziqaz: > such a shame, that phenom 1066 support kind of goes to waste

It has probably always been the case that during the launch of
a new tier of RAM speed, the early top tier stuff is not really
much faster than the next lower tier, unless you are running
a bandwidth-bound app mix.

Even if the 1066 were 133% faster in all respects (which it's not),
keep in mind that it's also two or three cache levels removed
from fetch-and-execute. As caches get bigger, and the possibility
of L4 cache looms, the impact of bumping one RAM tier gets even
harder to measure.
_______
RAM performance has been in big trouble ever since
CPUs began integrating cache.

[Karamiekos]

Thank you for this research Boundless. I think I will stick with some 800Mhz RAM when I build this folding machine....I mean you know for the wife......yeah, cause she needs a quad core to surf Facebook and check her yahoo mail......

[muziqaz]

Thank you for this research Boundless. I think I will stick with some 800Mhz RAM when I build this folding machine....I mean you know for the wife......yeah, cause she needs a quad core to surf Facebook and check her yahoo mail......

I don't know about facebook, but yahoo mail does need quad

[AussieFX]

Faster/more ram won't help with FAH. Just get the cheapest generic stuff you can find.

[AussieFX]

Boundless. I'm using 4x1gb 1066 with my 9850 and it's reporting all 4gigs (Vista x64 ultimate) and it's also reporting it as running at 1066. It's weird and goes against everything I have read. I think it must be reporting incorrectly. Although at 1066 I can't get my timings tighter than 5-5-5-18, if I set 5-5-5-15 it automatically changes tRAS to 18.

[raceb4us]

I have not looked at the datasheet but I suppose it is possible to run 4x1GB modules @1066MHz if they are single rank. Any thoughts on this?