Transcend JM366D643A-50

Transcend will be best known to some of our readers as a manufacturer of flash memory. While flash memory is an important product line for Transcend, they also manufacture storage products and system memory. You will not find Transcend for sale at a huge number of US websites, but Transcend also sells directly to end-users at their website. Transcend has US sites in both Spanish and English, as well as several European language sites, and Taiwan, Japan and China websites.

The 1 Gigabyte of DDR400 arrived as two separate 512MB DIMMs. Transcend packaging is very similar to that used by Kingston for their value products.

There are no heatspreaders on the Transcend CAS 2.5 DIMMs. The memory chips are labeled JetRAM, which is a name used by Transcend for their memory chips. A quick check found 1GB of Transcend CAS 2.5 selling for around $100, which is a lower price than what we normally see for a CAS 2.5 memory.


Transcend rates JM366D643A-50 at DDR400 CAS 2.5 and we found the "auto" or SPD timings to be 2.5-3-3-8.

 Transcend JM366D643A-50 (DDR400) Memory Specifications
Number of DIMMs & Banks 2 DS
Total Memory
512 MB
Rated Timings 2.5-3-3
SPD (Auto) Timings 2.5-3-3-8
Rated Voltage 2.6V

Transcend shows both DDR400 CAS 2.5 and DDR400 CAS 3 in their product list, so it is clear that the DIMM products from Transcend are aimed at the Value end of the memory market.

Test Results

Transcend JM366D643A-50 - 2 x 512Mb Double-Bank
CPU Ratio at 2.4GHz Memory
Memory Timings
& Voltage
Sandra UNBuffered Sandra Standard
Super PI 2M places
(time in sec)
Wolfenstein - Radar - Enemy Territory fps
12x200 400 DDR 2.5-3-3-6
2.6V 1T
532.0 INT 2420
FLT 2593
INT 6050
FLT 6036
82 111.9
11x218 436 DDR 3-3-3-6
2.8V 1T
529.2 INT 2593
FLT 2735
INT 6393
FLT 6309
82 111.7
Highest CPU/Mem Performance 3-3-3-7
2.8V 1T
575.5 INT 2668
FLT 2835
INT 6650
FLT 5516
75 122.5
To be considered stable for test purposes, Quake3 benchmark, UT2003 Demo, Super PI, Aquamark 3, and Comanche 4 had to complete without incident. Any of these, and in particular Super PI, will crash a less-than stable memory configuration.

Transcend is another memory that costs just $100 for a Gigabyte and yet manages to nearly reach DDR450 in overclocking. The cost and performance are very similar to the Kingston CAS 3 rated Value RAM except that Transcend rates its Value RAM at CAS 2.5. While the rated timings differ, both Kingston and Transcend both are stable at CAS 2.5 at DDR400. The Transcend RAM is an excellent value and provides the overclocking capabilities to reach a 12% CPU overclock at 1:1 memory ratio.

We have looked at Aida 32 results in the past, and found them to be very useful in examining read/write performance and memory latency. Aida 32 is now available as Everest Home Edition, a free download from

Transcend JM366D643A-50 (DDR400) 2x512Mb Double-Bank
Everest 1.51
CPU Ratio at 2.4GHz Memory Speed Memory Timings
& Voltage
Everest READ
Everest WRITE
Everest Latency
12x200 400 DDR 2.5-3-3-6
2.6V 1T
5801 1861 47.7
11x218 436 DDR 3-3-3-6
2.8V 1T
6028 1906 48.8
Highest CPU/Mem Performance
446 DDR
2.8V 1T
6306 1989 47.9

It is easy to see in the Everest results that dropping CAS just from 2.5 to 3 in moving from DDR400 to DDR436 offsets virtually all of the performance improvements that you get from higher memory speed. The $100 Transcend reaches on to DDR446 to give you most of the headroom that you need for air-cooled 1:1 overclocking at stock multipliers.

OCZ PC3200 Gold: "Value BH5" Performance Comparisons


View All Comments

  • segagenesis - Tuesday, April 12, 2005 - link

    Meh, I am lost for the life of me here. I dont see what the big fuss is over Value VX when I still cant find it. To save the comments this doesnt look like the memory reviewed in the article being 3-4-4-8.

    Seeing how is $87 and I already have some and know it works well... im hard pressed to think I really need to buy "mystery memory".
  • Illissius - Tuesday, April 12, 2005 - link

    Finally, is what I can say. However, if you really mean it when say you want to test real life performance, you should test with stuff from the actual standard benchmark suite - Quake 3 might show impressive gains from higher memory bandwidth, but does the same hold true for Doom 3?

    xsilver: While I agree that testing with the insane voltages available on DFIs limits the scope of the article somewhat, and results for lower voltages would've been nice to see (or at least mentioned specifically, it seems they're actually there for the BH5, though not the VX), I'm frankly more annoyed with all the other motherboard manufacturers for not allowing higher voltages (Abit in particular), than I am with AT for going ahead and testing with the only one that does. I wouldn't call it advertisement, more like a fair appraisal of capabilities.
  • Den - Tuesday, April 12, 2005 - link

    I thought it was interesting to see in the charts that the Crucial Balistix which are $204 right now ($106 each but 4% off if you buy two and therefore JUST missed the price cutoff for this review) were consistently very good (faster than almost everything in this review) and are the only ones that can be that fast on more normal (non-DFI) voltages. Reply
  • xsilver - Tuesday, April 12, 2005 - link

    Im not saying the dfi is bad or expensive.... its just that if you review with features that only the dfi can provide its not really a review / roundup anymore ..... its called an advertisment.... where's the choice?????
    I expect that dfi shareholders to be laughing really loud right now.... and OCZ too....
  • bigtoe36 - Tuesday, April 12, 2005 - link

    Value VX is $115 if you shop around, how does this count it out of a value roundup?

    Should AT have only reviewed value ram that performs poorly?
  • OrSin - Tuesday, April 12, 2005 - link

    #40 actually alot people would do just that.
    The DFI mother is not really that expensive.
    Asus and gigabit are the the same price. 6800GT cards are high but if you want the best cards you buy them, to play the games. But how many times have anyone said what type of ram you need to play Doom 3 or HL. No one. If you don't over clock, then $90 ram will slow you system down what 1-2% over $300 ram. I got a A64 3400 and 800XL and kingmax ram. And my system runs alot fat then my friend with with a just 800 and $250 ram.

    Sorry but buying high priced ram are mostly for over clockers and most people don't do that. Alot on these tech sites do, but my guess is even most people that buy $200+ ram don't

    The review was nice to me.
  • xsilver - Tuesday, April 12, 2005 - link

    another thing I want to clarify is that you make the assumption that you must be a "mad overclocker" if you buy the dfi because it can do 3.4v and all others that dont have the dfi are just posers..... many people would disagree but you seem to not notice???

  • xsilver - Tuesday, April 12, 2005 - link

    I understand what you say about making things consistent but arent then you just promoting the dfi board as no other board supports 3.4v? what about people who are going nforce 3 or intel (god forbid :P)
    in trying to maximize the potential of the ram, you are limiting the practical application...

    an analogy would be "in testing a ferrari its performance is great when drive it with brand X of fuel and feed it liquid oxygen".... umm... what about the rest of the people that dont use that?... that's why car reviews talk more about the "feel" & handling of the car, things that can be appriecieated by ALL customers....

    and by specifying that this review was more for "mad overclockers" that may use the dfi then why even review the cheaper solutions that dont even overclock at all... I mean its not exactly fair when you compare the really cheap ram to some OCZ VX values now is it?

    On one hand you try and generalize to the broader market but then on the other you say that you're only catering to the "mad overclockers" that buy the dfi
    your original scientific basis / aim is a little unsound
  • bigtoe36 - Tuesday, April 12, 2005 - link

    If your looking for value VX look here.

    Look closely at the part number is has WV which stands for with winbond die, timings are usually 3-4-4-8 or 2.5-3-3-8 buit its all the same stuff.
  • adg1034 - Tuesday, April 12, 2005 - link

    Where exactly can you find the Value VX? Do you have a model number? I was going to buy the Corsair Value RAM, but after reading this, I definitely think I'm going OCZ. Reply

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