Memory Scaling on Core i7 - Is DDR3-1066 Really the Best Choice?
by Gary Key on June 24, 2009 9:00 AM EST- Posted in
- Memory
Memory Pricing
We remember paying over $600 for 2GB of DDR3-1600 C7 rated at 1.90V almost two years ago. About nine months ago, when Core i7 launched a DDR3-1600 C7 6GB 1.65V kit cost us $415. A DDR3-1600 C7 1.65V 6GB kit cost us $140 last week. To add insult to injury, a recently purchased DDR3-1600 C9 1.65V 6GB kit set us back $86 compared to the $195 we paid four months ago. To say things have changed in the DDR3 memory market over the past two years would be an understatement.
In today’s testing, we did our best to utilize retail kits from various manufacturers based on their stock speed and timing ratings for each of our memory settings. We felt this was a better choice than taking a DDR3-2000 kit and using it at different speeds and timings as that would not represent what the actual product for sale at these price points are capable of in our test system. Of course, we violated this principal twice but for good reason. There are not any 1066 C5 kits so we bumped the voltage slightly on the Patriot 1066 C7 kit to run at these timings. Our 1866 C7 kit became incapacitated and we switched to a 2000 C8 kit that actually cost less and performed better.
The price levels listed represent our cost from Newegg at the time of purchase. Of course, prices for 6GB kits vary widely depending on the manufacturer, rebates, specifications, and product availability so consider these prices to represent a current aggregate average. We fully realize that purchasing a DDR3-2000 CAS8 kit for $235 that is capable of running DDR3-1866 C7 at like voltages is usually a better value than a $289 1866 C7 kit. Kit prices range from $80 for the DDR3-1066 C7 kit up to the $260 DDR3-2000 C8 modules for this article.
Our lead off contestant is the Patriot DDR3-1066 C7 PSD36G1066KH 6GB kit that we utilized for both the 1066 C7 and C5 results. This memory kit only required 1.60V for CAS5 operation and comes in at the low price of $80. For those operating on a strict budget, we cannot say enough good things about this kit as it easily reached DDR3-1600 C9 on 1.65V and 1.225V VTT. Speaking of DDR3-1600 C9 kits, we are now seeing these 6GB kits below $90 and if they arrive with the right IC/PCB combination, they could potentially make a great kit for down clocking to 1333 C6, which is one of our sweet spot settings for overall performance on this platform.
We tapped Corsair for our DDR3-1333 C9 kit, SuperTalent for the DDR3-1333 C8 modules, and GEIL for our DDR3-1333 C7/C6 kits. We turned to Patriot once again for DDR3-1600 C9, OCZ for a really great DDR3-1600 C8 setup, Corsair for DDR3-1600 C7, and Mushkin for one sweet DDR3-1600 C6 package. We utilized GSkill’s DDR3-2000 C8 kit for our DDR3-1866 C7 and limited overclock results. We will be reviewing each kit utilized shortly (and others) to determine the overall best value based on clocking abilities, technical support, warranty, and cost.
Memory Designations –
One of the more confusing aspects of selecting DDR3 memory are the two common designations, which are both technically wrong. The first commonly used term describes the theoretical bandwidth, as in PC16000. This numbering system represents the peak transfer rate in MB/s of the module. The other common designation describes the effective clock speed in terms like 2000MHz. If the product description does not contain the effective clock speed and you only see a number like PC8500, then divide it by eight. Therefore, through the magic of math and marketing, PC8500 becomes 1066MHz.
Of course, this is not the actual clock speed, but rather the data rate. In other words, while PC8500 sounds extremely impressive and 1066MHz just a little less so, the actual operating frequency of the DDR3 devices is much less. There is a history on why we have these inflated numbers as it dates back to the time of RAMBUS, but that is a story for another article. We just wish that the memory suppliers would pick one designation and go with it. In the meantime, we will report our numbers today in effective data rate for simplicity state. We will refer to DDR3-1066 5-5-5-18 as simply 1066 C5 as an example.
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BrianInfo - Thursday, July 30, 2009 - link
1.) The recommended DDR3-1066 Patriot PSD36G1066KH is non-ECC and unbuffered. Will this be an issue for the personal desktop use, mainly for video/audio transcoding/muxing?
2.) The article does not specify how to achieve the CAS5. Does anyone succeed the CAS5 with this Patriot DDR3-1066 and/or overclocked DDR3-1200?
3.) Is it possible to achieve the CAS5 with other brand, such as GeIL CAS7 GV36GB1066C7TC or Crucial CT3KIT25664BA1067??
4.) According to Tom's Hardware, not all the X58 motherboards support CAS5 http://www.tomshardware.com/reviews/cheap-x58-moth...">http://www.tomshardware.com/reviews/cheap-x58-moth...
so does it mean I cant obtain the ideal performance with the combination of "ASRock X58 Extreme" motherboard with "Patriot PSD36G1066KH" Tweaked-CAS5 DDR3? I really like the Asus P6T SE but the layout of the two (blue) PCI Express 2.0 x16 slots, too close to each other is killing me:(
iwodo - Sunday, June 28, 2009 - link
Spend the extra money on an SSD rather then faster Memory. Although i would love to see how Tri Channel differs from Dual Channel. ( Same results? )And how integrated Graphics differs in memory speed.
lemonadesoda - Friday, June 26, 2009 - link
Gary, you obviously get paid by wordcount. Too much waffle. Get to the meat faster.And what about this $200 between cheap and expensive DDR3 kits? How about seeing WHERE that $200 could have been spent in OTHER upgrades, ie. CPU or GPU, and running benchmark comparisons against THAT setup vs. the first.
Otherwise, thanks for running all the tests and creating the data for us to review :-)
PrinceGaz - Thursday, June 25, 2009 - link
As soon as I looked at the chart on the first page of the article, it was clear that the DDR3-1600 C9 memory would represent the best bang for the buck. It was only marginally higher priced than the DDR3-1066 C7 (and the DDR3-1066 C5 doesn't count as you overclocked the DDR3-1066 C7 for that purpose), and was sure to perform at least as good, and probably better than significantly higher priced DDR3-1333 modules at C8, and almost as good as the DDR3-1333 C7.Given that faster memory modules only ever have a negligible effect on real-world performance (unless you are a pirate and spend a lot of time using PAR2 checkers to rebuild damaged files from newsgroups, or WinRAR to then extract the original files, the sort of stuff I certainly won't say I do), then you may as well get the cheapest brand-name memory available. If you're spending in the upper mid-range on your CPU, then go for slightly faster (like the 1600 C9) but still quite cheap memory-modules. The only people who should be getting those top-of-the-range modules or anything close to that price level are those who have already decided on the fastest Core i7 CPU avilable (i7 975 currently), as otherwise they're wasting their money on the wrong bit of hardware.
Souka - Thursday, June 25, 2009 - link
I'm more confused than ever... what to buy?Putting together a new system...
Win7 or Vista x64
i7-920 CPU
x58 MB
ATI 4890 video
Memory? I'd like to go with 6GB (3x2gb), thought I had my choices narrowed down to:
Opt1: $138 mushkin 6GB(3x2GB) 1333(PC3 10666) Model 998706, Cas6, 6-7-6-18
Opt2: $175 mushkin 6GB(3x2GB) 1600(PC3 12800) Model 998691. Cas6, 6-7-6-18
But after reading this article, and your comments... I'm very uncertain....help!
PrinceGaz - Thursday, June 25, 2009 - link
Given a choice between either DDR3-1333 or 1600 memory with identical timings (6-7-6-18), but a $37 price difference, I'd probably go for the 1333, especially as you have decided on an i7-920. If you want to spend a little more to improve yours sytem performance, the memory speed is the last place to look at to do so.SiliconDoc - Sunday, July 5, 2009 - link
I took just the opposite from it - he has a 4980 there - overclockable nicely, is saving quite a bit with lower cpu, and what else can get him another 2,5,7,14 % in framerates, especially minimum in some cases ? I think the higher ram is much better and worth it after seeing this articles results.He will OC the 4890 and the cpu likely, so that fast ram will give it that great finisging kick and make it awesome.
Spend the $37 and be happy - definitely.
Hrel - Thursday, June 25, 2009 - link
G.Skill 1.5-1.6v 1333 Cas 8-8-8-21 = 65Crucial 1.8v 1333 Cas 6-6-6-20 = 64 (sold out right now)
OCZ 1.9v 1600 Cas 7-7-7-24 = 54 (after 20 mail in rebate)
Patriot 1.9v 1600 Cas 7-7-7-20 = 95 (free shipping)
Patriot 2.0v 1600 Cas 7-7-7-20 = 100 (Green, which I like)
So basically, it really ONLY makes sense to buy the OCZ 1600 Cas 7 for 54 bucks, why pay more for less?!!!
sonci - Wednesday, June 24, 2009 - link
Really boring for me,lucky, I didnt read it all
StraightPipe - Wednesday, June 24, 2009 - link
cough * troll*