Slow Memory

[shindawa]

I have a question maybe somebody can help me with. I have Kingston HyperX 3200 DDR Memory I purchased almost 2 years ago. There are 2 chips (total 1GB) that run at dual channel. My timings are 2.5-3-3-8. My motherboard is a Gigabyte 8KNXP. For some reason my memory scores are much lower than new 3200 DDR memory. Should I buy new memory, or is there some other problem?

Sisoft memory score new chips: 6000
My Sisoft memory score: 4500
Super Pi 2 million digits new chips: 80 seconds
My Super Pi: 130 seconds

 

[BrentUnitedMem]

What are the new modules you are using for comparison, what are the timings, and brand etc.. maybe they are just better.

Are you testing both modules with the same setup? The modules are placed in the same slots during both tests?



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[shindawa]

www.anandtech.com recently tested 12 different "Value memory" chips. Almost all of this memory is 1Gig of 3200 DDR with timings of 2.5-3-3-8. All of the memory chips have vitually identical performance numbers. Which as I noted, are significantly better than mine.

I guess my question is this - If different memory chips have almost identical specs, shouldn't they perform the same? I understand more expensive memory can usually be overclocked more aggressively and may be more stable. But my problem does not concern overclocking or stability.

 

[fishmahn]

They will perform the same on the same platform, but performance will be different when you change the motherboard from an nForce4 one to an I875 one. There will even be a difference (though much smaller) when switching from a DFI to Gigabyte to Asus, etc., within the same platform.

Additionally, the Athlon64 test bed used in your comparison has the memory controller on the CPU die, so memory latency is drastically reduced, increasing memory performance over that of an Intel system who's memory controller is on the northhbridge.

Compare apples and apples instead of apples and oranges, and you may find your memory performance more competitive.

Mike.

 

[BrentUnitedMem]

If different memory chips have almost identical specs, shouldn't they perform the same?

Not at all. Only in some cases.

The reason is that semiconductor manufacturers aim for a general specification. And often the results are much better, slightly better, or on par with the general specification, or even worse then the specification.

For example, a given process may test a few hundred parameters on a memory chip for a DDR-400 specification. The resulting chips may be classified as follows for the spec:

200/200 pass: Chip is labeled as DDR-400.
In fact.. many of the chips are capable of DDR500+

190/200 pass: chip is labeled as DDR-333.
No possibility of reaching DDR-400

180/200 pass: chip is labeled as DDR-266.
No possibility of reaching DDR-333

< 180/200 pass: bad chips or sold as downgraded parts.

Some companies like Samsung and Hynix offer DDR-500 chips. Of course, they have to perform a high standard test. However, no company officially supports DDR-500 chips.

By the way.. contrary to popular belief.. there is no standard for DDR-400 CL2 or CL2.5. You will see that modules with these ratings are built from chips that are offically rated at DDR-400 CL3. It's just that the third parties who buys these chips perform additional testing to ensure they run at DDR-400 CL2 or CL2.5.

Expensive memory is just tested more often. =)

Lower latency modules are geared towards gamers and enthusiasts, where data integrity and application compatibility are not as important as perfromance. AKA overclockers. hehe

Most professional workstations follow standard specification.

<A HREF="http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=114786#114786" target="_new">Another somewhat related thread</A>

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"Memory with lifetime warranty? So, whose lifetime is that?"
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AIM BrentUnitedMem

 

[shindawa]

Thanks for the help guys.

 

[BrentUnitedMem]

Basically I was just saying that for modules that pass the highest test, even for the same chip type.. the performance can vary significantly.

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"Memory with lifetime warranty? So, whose lifetime is that?"
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AIM BrentUnitedMem