Stock Memory Performance
Most Intel Socket T (Socket 775) motherboards provide a wide range of memory ratios that match available DDR2 memory. End-users can select the memory ratio that matches their DDR2 memory speed. Our memory testing begins with the same approach. We first test all of the stock ratios at the fastest stable timings we can achieve at the given ratio. With ratios, CPU speed remains the same at 2.93GHz in our memory test bed, and memory speed is varied by selecting different ratios.
There are some downsides to this approach. With the memory controller in the chipset, instead of part of the processor as in AM2 systems, there is a small performance penalty for speeds other than a 1:1 ratio (DDR2-533 in this case). The performance penalty is actually very small and has minimal impact on test results. As a result memory scales nicely through the various speed options.
DDR2 memory is then pushed from the highest stock ratio that could be achieved in testing - in this case 1067 - to the highest FSB speed at the stock multiplier. In the case of the G.Skill DDR2-800 speeds higher than DDR2-1067 were not completely stable. While we could boot as high as DDR2-1100 we could not complete our memory benchmarks at speeds above DDR2-1067 with the maximum 2.4V available on the ASUS P5W-DH. Boards with an extended top voltage range, like the DFI 590 for AM2, may be able to squeeze even more performance from these G.Skill DIMMs.
It is also worth pointing out that two sets of DDR2-800 benchmarks were run. The G.Skill memory required more voltage than the more expensive Micron D9 chips to perform with stability at 3-3-3 DDR2-800 timings. The great news is that they could match the fast 3-3-3 timings we have seen on other Micron D9, but they required 2.35V to do this, where the more normal required voltage is 2.2V.
Many buyers of mid-range DDR2-800 memory will not have a high-end motherboard that can supply voltages like 2.35V in their system. For that reason we also tested the specified 4-4-4 timings at DDR2-800. Those results were a very pleasant surprise since we achieved stability with just 1.9V at 4-4-4-12 timings. This is a voltage that any Core 2 Duo or AM2 motherboard should be able to deliver.
You can also see that 2.35V was required to reach stable performance at DDR2-1067. The good news is that the G.Skill DDR2-800 can be overclocked to DDR2-1067, but you will need voltage to reach that overclock. While we did not include results in the chart we did try to see how far we could push the G.Skill with 5-5-5-15 timings and a more modest 2.0V. The memory remained stable to just above DDR2-1000 at 2.0V.
This performance pattern gives most every buyer some choices when using this G.Skill DDR2-800 in their system. If their board is voltage limited, the memory is still usable at slightly slower timings. If the board supplies a very wide voltage range, then you can likely squeeze even better timings from this memory with higher voltage.
Most Intel Socket T (Socket 775) motherboards provide a wide range of memory ratios that match available DDR2 memory. End-users can select the memory ratio that matches their DDR2 memory speed. Our memory testing begins with the same approach. We first test all of the stock ratios at the fastest stable timings we can achieve at the given ratio. With ratios, CPU speed remains the same at 2.93GHz in our memory test bed, and memory speed is varied by selecting different ratios.
There are some downsides to this approach. With the memory controller in the chipset, instead of part of the processor as in AM2 systems, there is a small performance penalty for speeds other than a 1:1 ratio (DDR2-533 in this case). The performance penalty is actually very small and has minimal impact on test results. As a result memory scales nicely through the various speed options.
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| Click to enlarge |
DDR2 memory is then pushed from the highest stock ratio that could be achieved in testing - in this case 1067 - to the highest FSB speed at the stock multiplier. In the case of the G.Skill DDR2-800 speeds higher than DDR2-1067 were not completely stable. While we could boot as high as DDR2-1100 we could not complete our memory benchmarks at speeds above DDR2-1067 with the maximum 2.4V available on the ASUS P5W-DH. Boards with an extended top voltage range, like the DFI 590 for AM2, may be able to squeeze even more performance from these G.Skill DIMMs.
It is also worth pointing out that two sets of DDR2-800 benchmarks were run. The G.Skill memory required more voltage than the more expensive Micron D9 chips to perform with stability at 3-3-3 DDR2-800 timings. The great news is that they could match the fast 3-3-3 timings we have seen on other Micron D9, but they required 2.35V to do this, where the more normal required voltage is 2.2V.
Many buyers of mid-range DDR2-800 memory will not have a high-end motherboard that can supply voltages like 2.35V in their system. For that reason we also tested the specified 4-4-4 timings at DDR2-800. Those results were a very pleasant surprise since we achieved stability with just 1.9V at 4-4-4-12 timings. This is a voltage that any Core 2 Duo or AM2 motherboard should be able to deliver.
You can also see that 2.35V was required to reach stable performance at DDR2-1067. The good news is that the G.Skill DDR2-800 can be overclocked to DDR2-1067, but you will need voltage to reach that overclock. While we did not include results in the chart we did try to see how far we could push the G.Skill with 5-5-5-15 timings and a more modest 2.0V. The memory remained stable to just above DDR2-1000 at 2.0V.
This performance pattern gives most every buyer some choices when using this G.Skill DDR2-800 in their system. If their board is voltage limited, the memory is still usable at slightly slower timings. If the board supplies a very wide voltage range, then you can likely squeeze even better timings from this memory with higher voltage.
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christopherzombie - Sunday, November 5, 2006 - link
I have the same G.Skill "HZ" kit and I can do 1066mhz @ 5-5-5-15 with only 2.2v on an Abit AN9 32X 590SLI. I run at this speed 24/7 with my X2 4000+ @ 2.66ghz. No issues here. Great RAM for the money. I'm glad I didn't speed 50% more $$ for Cosair.formulav8 - Saturday, November 4, 2006 - link
I guess its just me, but I would think spending $300 for 2GB of memory is the absolute high-end prices. Even with the overall price increase of memory. I guess I am just poor :(Jason
Wesley Fink - Saturday, November 4, 2006 - link
Let's be VERY CLEAR. We are talking about TWO GIGABYTES of memory, which has become the new standard with Vista on the way. The absolute cheapest generic 2GB kit I could find on NewEgg runs am average of $200 - and it is generally DDR2-533. You can find Value DDR2-800, rated at 5-5-5 which we mention in the review, for $210 to $250. The DDR2-800 4-4-4 we tested was $299 - $99 more than the average low-end 2GB kit we could find at a reputable e-tailer. It also does 3-3-3 at 800 and 1067 since it is based on Micron D9 chips - if you can supply the voltage.YOU have to decide if it is worth it to spend $99 more for higher rated memory that can do 3-3-3 at DDR2-800 with voltage, 4-4-4 with no voltage, and DR2-1066. If you are shopping for a 1GB kit, the cost for 2x512MB is about half this amount. Until the move to DDR2, we always tested a 1GB kit. We moved the total up when 2GB became more common and it was clear Vista would need 1GB as a minimum.
xFlankerx - Saturday, November 4, 2006 - link
I think people aren't realizing that this is DDR2-800 memory, not DDR2-533. As such, it is Overclocking memory, and the prices are proportional to what the prices were for, say, a DDR600 memory kit for the AMD platform.I have the utmost respect for AT reviews, and your analyses, but when I read "Mid-Range" and saw the pic of the GBHZs (my favorite memory, from the AMD days), that left me a bit confused. I design PCs for others as a hobby, as do many many other people. And anyone who does knows that very few people are going to be willing to spend $300 on memory that they don't really need. Also, I'm a huge proponent of Memory Dividers, as they help majorly, and don't make you sacrifice performance.
The prices for the enthusiast memory may be proportional, however they are still VERY high. The massive FSB potential and overclocking of the Core 2 Duos has made it mandatory that you use high-speed memory in your system. DDR2-533 simply won't overclock far enough. So we HAVE to use DDR2-800 like we used DDR400. And with Vista requiring 2GB, the memory prices need to be much LOWER than they are right now. Going from $100 for 1GB DDR400 for a smooth and overclocked system, to needing to spend $250 for 2GB DDR2-800 for a smooth and overclocked system is a hard slap in the face for most people, including designers. As one of the people I was designing for pointed out, "Its a sad day when your memory costs more than your processor."
xsilver - Sunday, November 5, 2006 - link
I would just like to clear up something further as their are many conflicting views.is it possible to use ddr667 ram and still not hit the wall with your ram until 500FSB or so?
Using dividers of course, and taking the 5% hit in performance? (its not even 5% is it?)
Isnt this the best way to build a overclocking system on a budget?
I agree with Wes when he says that this ram is really only $99 more expensive than base ram but I guess its just the sad state that the ram market is in and people are looking for the best value they can. So categorizing $300 ram as "semi-performance" ram is just sad to see.
Steve Guilliot - Friday, November 3, 2006 - link
... "paying through the nose gets you miniscule performance gains"?The core architecture has never been memory bandwidth starved, and every single memory article seems to re-inforce that. Why didn't Wesley use 0 fps as the baseline for his scatter plots? Becuase if he did, the results wouldn't be exaggerated enough to notice on the graph. Doesn't that tell you something?
Sorry, but 1% gain is not worth spending and extra $200 on 1066 memory. That would be useful advice that needs to be reinforced when the money could be spent on better graphics or processing or monitor. Instead, the enthusiast community seems bent on justifying it's fascination with fast memory.
Look, memory was important with the P4, but let's move on and recognize that Core does not need fast memory.
Sorry for the soapbox, and this is not just a problem with Anandtech; it's on all the enthusiast sites.
JarredWalton - Friday, November 3, 2006 - link
High quality memory is important for overclocking. If your RAM can't go beyond DDR2-800, an E6300 would be limited to a maximum OC of 2.8 GHz - still fast, but a lot of people are hitting 3.2GHz+. An E6400 would be able to hit 3.2 GHz at DDR2-800 (with 1:1 ratio), and again you can almost certainly go further.As Wes states on page 5: "Memory speed can definitely improve system performance, but not to the extent of an upgraded video card or a higher speed processor." If you've already maxed out the other areas, or at least come close, then you will probably be willing to spend more on RAM as well. If you're pinching pennies elsewhere, then RAM is probably not going to be something you want to spend a ton on either. Of course, these days $300 for good quality 2GB kits isn't really that bad.
Steve Guilliot - Saturday, November 4, 2006 - link
Also, even if someone had "maxed" out other areas, I still wouldn't recommend throwing away money on faster RAM. If you're even above entry level, then you have at least a x9 multiplier. DDR2-667 will be fine for maintaining the ideal 1:1 divider while overclocking. Ok, let's stretch it to DDR2-800 for giggles. But DDR2-1066? Please.I suppose a fool is easily seperated from their money, but most people who have money value it. My recommendations alway involve eliminating waste no matter how much someone is willing to spend.
Steve Guilliot - Saturday, November 4, 2006 - link
So, you would recommend $300 RAM to someone who couldn't afford to pay more than $163 for an e6300, or $200 for an e6400? ... and e6600's are only $280.The statement "Memory speed can definitely improve system performance" is what set me off in the first place, since it is a gross exaggeration and underpins the focus of the article. I know the enthusiast community is a benchmark driven one, but cmon: 1% is not a definite improvement. Consistent maybe, but "definite" implies "noticable". Nope, 1% is not noticeable.
On a related note, most of my ranting is equally applicable to the quest for ever-higher FSB's.
xsilver - Friday, November 3, 2006 - link
cant u use memory dividers instead?I dont have a core system, but I would suspect that you can run something close to ddr 800 at 400fsb?
and then use the extra saved cash for a better video card/cpu?