DDR3-1333 Speed and Latency Shootout

By Thomas Soderstrom
published

SPD Timing Comparison

Though we will find the lowest stable timings at increased voltage in our later "lowest stable latency" tests, a chart comparing all the rated timings should help determine which market each module set is really targeting.

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Automatic Configuration Data (MHz: tCL-tRCD-tRP-tRAS)
Brand/Model/Part NumberDetectedSPD TimingsRated SettingsSPD Extensions
Aeneon667: 8-8-8-15416: 5-5-5-15DDR3-1333,None
X-Tune DDR3-1333Row 2 - Cell 1 500: 6-6-6-18CAS 8-8-8-15,Row 2 - Cell 4
AXH760UD00-13GRow 3 - Cell 1 667: 8-8-8-241.50 VRow 3 - Cell 4
Row 4 - Cell 0 Row 4 - Cell 1 750: 9-9-9-27Row 4 - Cell 3 Row 4 - Cell 4
G.Skill667: 9-9-9-24444: 6-6-6-16DDR3-1333,None
PC3-10600Row 6 - Cell 1 592: 8-8-8-22CAS 9-9-9-24,Row 6 - Cell 4
F3-10600CL9D-2 GBNQRow 7 - Cell 1 667: 9-9-9-241.50-1.65 VoltsRow 7 - Cell 4
Kingston667: 8-8-8-24416: 5-5-5-15DDR3-1333,None
ValueRAM PC3-10600Row 9 - Cell 1 500: 6-6-6-18CAS 8-8-8-24,Row 9 - Cell 4
KVR1333D3N8/1GRow 10 - Cell 1 583: 7-7-7-211.50 VoltsRow 10 - Cell 4
Row 11 - Cell 0 Row 11 - Cell 1 667: 8-8-8-24Row 11 - Cell 3 Row 11 - Cell 4
Kingston533: 7-7-7-20457: 6-6-6-18DDR3-1333,None
HyperX PC3-11000Row 13 - Cell 1 533: 7-7-7-20CAS 7-7-7-20,Row 13 - Cell 4
KHX11000D3LLK2/2GRow 14 - Cell 1 609: 8-8-8-231.70 VoltsRow 14 - Cell 4
Mushkin Enhanced667: 9-9-9-24444: 6-6-6-16DDR3-1333,None
EM3-10666Row 16 - Cell 1 518: 7-7-7-19CAS 9-9-9-24,Row 16 - Cell 4
996583Row 17 - Cell 1 667: 9-9-9-241.50 VoltsRow 17 - Cell 4
OCZ Technology667: 7-7-7-20476: 5-5-5-15DDR3-1333,None
PC3-10666 Platinum EditionRow 19 - Cell 1 571: 6-6-6-18CAS 7-7-7-20,Row 19 - Cell 4
OCZ3P13332GKRow 20 - Cell 1 667: 7-7-7-201.80 VoltsRow 20 - Cell 4
Row 21 - Cell 0 Row 21 - Cell 1 761: 8-8-8-23Row 21 - Cell 3 Row 21 - Cell 4
OCZ Technology533: 6-5-5-20533: 6-5-5-20DDR3-1333,None
PC3-10666 ReaperXRow 23 - Cell 1 622: 7-6-6-24CAS 6-5-5-18,Row 23 - Cell 4
OCZ3RPX1333EB2GKRow 24 - Cell 1 711: 8-7-7-271.85 VoltsRow 24 - Cell 4
Patriot Extreme Performance533: 7-7-7-20457: 6-6-6-18DDR3-1333,None
PC3-10666 Low Latency KitRow 26 - Cell 1 533: 7-7-7-20CAS 7-7-7-20,Row 26 - Cell 4
PDC34G1333LLKRow 27 - Cell 1 Row 27 - Cell 2 1.70 VoltsRow 27 - Cell 4
Super Talent533: 7-7-7-20533: 7-7-7-20DDR3-1333,XMP-1600
PC3-10600 CL8Row 29 - Cell 1 609: 8-8-8-23CAS 8-8-8-18,CL 8-8-8-28
W1333UX2G8Row 30 - Cell 1 Row 30 - Cell 2 1.80 Volts2.00 V
Wintec Industries533: 8-8-8-20400: 6-6-6-15DDR3-1333,None
AMPX PC3-10600Row 32 - Cell 1 533: 8-8-8-20CAS 9-9-9-24,Row 32 - Cell 4
3AHX1333C9-2048KRow 33 - Cell 1 Row 33 - Cell 2 1.50 VoltsRow 33 - Cell 4

Aeneon and OCZ both provide SPD values in excess of their rated speed, while Super Talent uses Intel XMP automatic overclocking capabilities to go even higher. Kingston and PDP Patriot instead target the low-latency crowd, but OCZ appears to shoot for both markets with both of its products.

Thomas Soderstrom
Thomas Soderstrom
Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.
6 Comments Comment from the forums
  • dv8silencer
    I have a question: on your page 3 where you discuss the memory myth you do some calculations:


    "Because cycle time is the inverse of clock speed (1/2 of DDR data rates), the DDR-333 reference clock cycled every six nanoseconds, DDR2-667 every three nanoseconds and DDR3-1333 every 1.5 nanoseconds. Latency is measured in clock cycles, and two 6ns cycles occur in the same time as four 3ns cycles or eight 1.5ns cycles. If you still have your doubts, do the math!"

    Based off of the cycle-based latencies of the DDR-333 (CAS 2), DDR2-667 (CAS 4), and DDR3-1333 (CAS8), and their frequences, you come to the conclusion that each of the memory types will retrieve memory in the same amount of time. The higher CAS's are offset by the frequences of the higher technologies so that even though the DDR2 and DDR3 take more cycles, they also go through more cycles per unit time than DDR. How is it then, that DDR2 and DDR3 technologies are "better" and provide more bandwidth if they provide data in the same amount of time? I do not know much about the technical details of how RAM works, and I have always had this question in mind.
    Thanks
    Reply
  • Latency = How fast you can get to the "goodies"
    Bandwidth = Rate at which you can get the "goodies"
    Reply
  • So, I have OCZ memory I can run stable at
    7-7-6-24-2t at 1333Mhz or
    9-9-9-24-2t at 1600Mhz
    This is FSB at 1600Mhz unlinked. Is there a method to calculate the best setting without running hours of benchmarks?
    Reply
  • Sorry dude but you are underestimating the ReapearX modules,
    however hard I want to see what temperatures were other modules at
    a voltage of ~ 2.1v, does not mean that the platinum series is not performant but I saw a ReapearX which tended easy to 1.9v(EVP)940Mhz, that means nearly a DDR 1900, which is something, but in chapter of stability/temperature in hours of functioning, ReapearX beats them all.
    Reply
  • All SDRAM (including DDR variants) works more or less the same, they are divided in banks, banks are divided in rows, and rows contain the data (as columns).
    First you issue a command to open a row (this is your latency), then in a row you can access any data you want at the rate of 1 datum per cycle with latency depending on pipelining.

    So for instance if you want to read 1 datum at address 0 it will take your CAS lat + 1 cycle.

    So for instance if you want to read 8 datums at address 0 it will take your CAS lat + 8 cycle.

    Since CPUs like to fill their cache lines with the next data that will probably be accessed they always read more than what you wanted anyway, so the extra throughput provided by higher clock speed helps.

    But if the CPU stalls waiting for RAM it is the latency that matters.
    Reply
  • what is on pc3-10600s "s" ?
    Reply