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OCZ shows external USB 3.0 SSD, new PSUs

By Matthew
Jan 8, 2010
  1. Along with OCZ's upcoming Vertex 2, SAS and PCIe SSDs, the company has also unveiled a 2.5-inch USB 3.0 external SSD, a couple of power supplies. The portable SuperSpeed USB SSD features MLC flash memory in capacities of 64GB, 128GB and 256GB, is encased in aluminum, measures 56 x 120 x 10 millimeters, and weighs 87.7 grams.

    Read the whole story
     
  2. raybay

    raybay TS Evangelist Posts: 7,241   +9

    How do they define 85% power efficiency and 88% power efficiency... against what standard ? What is special about 135 mm double ball-bearing fans, which can actually be more trouble than they are worth.
     
  3. dividebyzero

    dividebyzero trainee n00b Posts: 4,891   +1,251

    Power efficiency like the 80+ rating you see applied to many psu's is calculated at different power draws - 20%, 50% and 100%
    So,for example if the PSU is rated at 85% efficiency then for a 750 watt power supply it can deliver 85% of the 750 watts ( 0.85 x 750 = 637.5 watts), the remaining 15% is converted into heat ( 112.5 watts)
     
  4. dividebyzero

    dividebyzero trainee n00b Posts: 4,891   +1,251

    The power draw is calculated at 20%, 50% and 100% of its rated power load and the lowest value is generally accepted as the power efficiency -although some manufacturers fudge the numbers by quoting only one of the three values- Hence the adoption of the 80+ certification:
    80% power efficiency at 20, 50 and 100% = 80+ certification, so you need at least:
    81/82% at 20% draw, 85% at 50% draw and 81/82% at 100% draw = 80+ Bronze cert.
    85% at 20% draw, 88/89% at 50% draw and 85% at 100% draw = 80+ Silver cert.
    87/88% at 20% draw, 90/92% at 50% draw and 87/88% at 100% draw = 80+ Gold cert.
    90% at 20% draw, 94% at 50% draw and 91% at 100% draw = 80+ Platinum cert.

    Fan size and capability is either an advertising ploy or because the power supply needs that much cooling (i.e. generates a lot of heat) and yes bb fans are usually noisy. Taking the PSU apart and replacing the fan with a fluid or electromagnetic drive will usually cure the problem)
    I wouldn't recommend taking apart a PSU that has already been in use as the capacitors store a charge long after the power supply has laid dormant.

    Sorry about the double post- hit the wrong button before- loooong day.
     
  5. Regenweald

    Regenweald TS Rookie Posts: 143

    You just clarified a lot about psu tech for me. Thanks man :)
     
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