4GB Gets Cheap: 9 Dual-Channel Kits Compared

Latency And Overclocking Results

While previous DDR2 tests were often stopped at CAS 5, one of the module sets in today’s competition was rated at super-relaxed latencies of CAS 7. With high hopes that several of these memory kits might reach a 1,200 MHz data rate, we tried latencies ranging from CAS 3 to CAS 8 before determining the “Lowest Latency” for data rates of 800, 1,066, and 1,200 MHz.

Many users fear added voltage may cause premature parts failure, so we started with the DDR2-standard 1.80 V setting and worked our way up. Modules are sorted by best latency, starting with the highest achievable speed.

Swipe to scroll horizontally
DDR2-1200DDR2-1066DDR2-800
G.Skill F2-8000CL5DFailed5-5-4-144-4-3-10
Crucial Ballistix PC2-6400Failed5-5-5-144-4-4-10
Patriot Viper 6400LLKFailed6-6-5-64-4-4-5
Kingston KHX8500AD2Failed6-5-6-155-4-4-12
PNY MD4096KD2-800-X4FailedFailed4-4-3-10
Super Talent T800UX4GC5FailedFailed4-5-3-5
Corsair XMS2-6400C5FailedFailed5-4-4-10
Mushkin 996557FailedFailed5-4-4-10
Wintec AMPX 6400C5FailedFailed5-4-4-10

While none of our module sets were capable of reaching DDR2-1200 at standard voltage, G.Skill’s DDR2-1000 and Crucial’s Ballistix DDR2-800 both reached DDR2-1066 at CAS 5. Kingston’s DDR2-1066 didn’t require a voltage increase to reach its rated speed, but it suffered from longer CAS 6 latency requirements.

At the basic DDR2-800 setting, Patriot’s low-latency kit stands out for having exceptional tRAS.

Swipe to scroll horizontally
DDR2-1200DDR2-1066DDR2-800
Crucial Ballistix PC2-64006-5-6-155-4-5-144-3-4-10
G.Skill F2-8000CL5DFailed5-5-4-144-4-3-10
Patriot Viper 6400LLKFailed5-5-5-64-4-4-4
Kingston KHX8500AD2Failed6-5-6-155-4-4-12
PNY MD4096KD2-800-X4FailedFailed4-4-3-9
Corsair XMS2-6400C5FailedFailed4-4-4-10
Super Talent T800UX4GC5FailedFailed4-5-3-5
Mushkin 996557FailedFailed5-4-4-10
Wintec AMPX 6400C5FailedFailed5-4-4-10

A modest voltage increase to 2.00 V returned amazing results from Crucial Ballistix, with a 50% overclock achieved ! The stigma of using CAS 6 timings goes away at DDR2-1200, since this 50% increase in latency cycles (compared to rated timings) is accompanied by an equally significant decrease in cycle time (compared to rated speed).

Patriot’s low-latency kit again offers impressively-low tRAS, with the added voltage bringing it down to four cycles.

Swipe to scroll horizontally
DDR2-1200DDR2-1066DDR2-800
Crucial Ballistix PC2-64006-5-6-155-4-5-144-3-4-10
Patriot Viper 6400LLK7-7-7-115-5-5-64-4-4-4
G.Skill F2-8000CL5DFailed5-5-4-144-4-3-10
Kingston KHX8500AD2Failed6-5-6-155-4-4-12
PNY MD4096KD2-800-X4FailedFailed4-4-3-8
Corsair XMS2-6400C5FailedFailed4-4-4-10
Super Talent T800UX4GC5FailedFailed4-5-3-5
Mushkin 996557FailedFailed5-4-4-10
Wintec AMPX 6400C5FailedFailed5-4-4-10

Crucial’s Ballistix DDR2-800 continues its lead at 2.20 V, but doesn’t show any gains compared to its 2.00 V results. Patriot breaks through the DDR2-1200 ceiling as well, but at lengthier CAS 7 timings.

None of the remaining modules showed notable performance gains in the switch from 2.00 V to 2.20 V, but we still used 2.20 V as the limit when we moved on to seek the maximum clock speed of each module set. Hoping that several modules would at least come close to a 1,200 MHz data rate at reasonable timings, we chose latency limits of 6-6-6-18.

Crucial Ballistix PC2-6400 isn’t the cheapest memory around, but its overclocking potential is nothing short of stunning. Only Patriot Viper PVS24G6400LLK was able to come close.

Some of our samples were rated at far higher speeds than the DDR2-800 of Crucial’s mid-priced Ballistix, but it’s obvious that “overclock-validated” parts are not always the best choice for overclockers. A comparison of rated-speed to achieved speed adds a little more perspective.

The two “high-speed” memory kits were among the worst overclockers, percentage wise. Anyone who is willing to pay extra for overclocking-validation will be especially disappointed in the chart above, as its shows that the only reliable way to estimate how far a memory set will go is to read reviews. Since manufacturers often alter components without telling anyone, user reviews are a great way to stay updated once an official review no longer appears relevant.

While overclocking and low latencies are nice features, the focus of today’s comparison is performance value, also known as “bang for the buck." Our next page will show the value of each kit, from several perspectives.

Thomas Soderstrom
Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.
  • randomizer
    Good to see G.Skill finally decided to send some samples.
    Reply
  • JonnyDough
    You can increase how much ram is used for prefetch in XP as well, so that hardly says that Vista is faster than XP once you use more RAM. I for one have skipped the Vista era and am happily awaiting Windows 7. I guess I prefer to keep my $100 in my wallet for awhile instead of giving it to M$ investors.
    Reply
  • V3NOM
    i rofl'd that my cheap Team Elite owned all of them except the ballistix...
    Reply
  • JonnyDough
    Stop using rebates as qualifiers. I was taught in consumer math that if you purchase something with the cost of a rebate figured in, you had better be prepared to pay full price. I think a lot of us here IGNORE rebate pricing, and won't even support it by buying rebated items. Rebates are CRAP, no consumer likes them. They aren't a "discount" they are a marketing ploy to rip people off.
    Reply
  • raider37
    I'm pretty darn happy with my 4GB of XMS2 DDR2-800 RAM from Corsair, all my components are overclocked and work extremely well, plus here in Pakistan only 2 memory companies are widely available (Kingston and corsair) and we all know kingston is overpriced and their modules do not perform as well as Corsairs.
    Reply
  • johnbilicki
    As a regular I feel insulted that my fellow readers and I are expected to except an introduction suggesting that we are mindless consumers no different than the people who trampled and killed a worker at Walmart this past Friday.

    My dual core socket 939 with 2GB of RAM running XP Pro might not get as much FPS as my friend running a quad with 4GB and Vista but my system runs smooth on almost all the same games without dealing with all the constant freezing, errors, glitches, and horrendous boot times plus I don't have to run a page file. A real enthusiast would turn in their grave if they saw qttask in the task manager. Real pride is knowing your rig's software too and mindlessly burning money instead doing a few simple Google queries is what an amateur would do.

    I expect better than this. It does really matter.
    Reply
  • Crashman
    johnbilickiAs a regular I feel insulted that my fellow readers and I are expected to except an introduction suggesting that we are mindless consumers no different than the people who trampled and killed a worker at Walmart this past Friday.
    That sounds like the voice of experience...you were at that Wal Mart? Because it appears that everyone else automatically knew that the introduction was meant to cover the widest range of potential buyers, and not each one of them specifically. Yet you mindlessly trampled into that rant?
    Reply
  • johnbilicki
    CrashmanThat sounds like the voice of experience...you were at that Wal Mart? Because it appears that everyone else automatically knew that the introduction was meant to cover the widest range of potential buyers, and not each one of them specifically. Yet you mindlessly trampled into that rant?
    The introduction slaps everyone in the face by suggesting money is the only solution. Even less experienced people know how to do a Google query.

    "The power of accurate observation is commonly called cynicism by those who haven't got it." - George Bernard Shaw
    Reply
  • Crashman
    johnbilickiThe introduction slaps everyone in the face by suggesting money is the only solution. Even less experienced people know how to do a Google query."The power of accurate observation is commonly called cynicism by those who haven't got it." - George Bernard Shaw
    It suggests that very little money can be a very easy solution to multiple performance issues.

    And you're using a quote to emphasise your cynicism concerning my observation? Thanks!
    Reply
  • johnbilicki
    CrashmanIt suggests that very little money can be a very easy solution to multiple performance issues.And you're using a quote to emphasise your cynicism concerning my observation? Thanks!
    ...and entirely avoids the point of optimizing a system's software just as you have! It's an informal fallacy to suggest you have made some unique observation as I have when all you have done is avoid my point in the simple interest to convince people to spend money instead of simply preventing junk from being loaded in to their existing memory.
    Reply