Dell T3400.. Do You Have DDR2-800 Memory?

Discussion in 'Hardware' started by gnome, Mar 24, 2008.

  1. Would someone please check and report to this thread?

    Most DDR2 800 runs on 2.2v, but some runs on 1.8v.... Don't know which is Dell.

    It's also possible that your Dell would "run" DDR2-800, but step it down to only DDR2-667 on 1.8v.

    Please list (1) Voltage, and (2) Timings

    Here's a link for the latest CPU-Z if you need it. (You can run it from a flash drive.)

  2. I know for a fact that Crucial lists DDR2-667 NON-ECC memory for the Precision T3400 at 1.8 volts.

    The DDR2-800 memory for the T3400 is only ECC. I believe that it also runs at 1.8 volts, whereas most of your high performance RAM manufacturers like Corsair are running their speedy memory at much higher voltages, anywhere from 2.1-2.7

    The T3400 owner's manual does not show any voltage info on the RAM:

    See Page 33

    P.S. The optional 525 power supply unit for the T3400 has THREE +12v rails rated at 18a.
  3. So, you got the DDR2-800, ECC? I thought you were against that because of some "latency" issue..... ??

    And, there IS some DDR2-800 @ 1.8v and 1.9v available... small by comparison to the number of higher voltage offerings, though.

    And you know Crucial... if you use their "RAM Selector", they guarantee compatibility or they will buy it back. And they list "DDR2-800 @ 2.2v as compatible" for my 1.8v D9200... I wonder how that works out?
  4. I got the 800 MHz DDR2 ECC memory because that is the only memory that Dell offered at the "800" speed.

    The CAS latency appears to be "6" on the Crucial and Kingston memory. A Dell rep told me that their "White Papers" on memory show the CL to be "5" at the 800 MHz level. We shall see once I get the unit and use "CPU-Z"

    What apparently is the REAL driver in latency lies in the difference between "registered" ( buffered ) RAM and non-registered ( unbuffered ) RAM.

    Registered RAM can be thought of as running one full clock cycle "behind" an equivalent unregistered DRAM.

    The reason this is, is because the "registered" modules have additional components ( registers ) placed between the incoming address and control info and the SDRAM components.

    As a result, it is thought to be the most scalable and stable RAM. Mostly used in servers.

    Getting back to our example of ECC and non-ECC . . . "Registered" memory can be found in either.

    So what actually adds to the latency is whether or not the memory is "registered" or not ( unbuffered ). The performance "hit" from ECC is incredibly small, negligible in fact. So, in reality running ECC is a non-issue from a performance standpoint.

    Depending on what kinds of applications you are running, Unbuffered memory appears to run 10% - 15% faster than "registered".

    Note: The DDR2 memory for the T3400 is unbuffered

  5. The standard for 800Mhz (PC6400) DDR 2 ram is:

    5-5-5-18, cas 5, 1.8v

    Lower cas numbers and higher voltages are good for overclockers.
  6. keep in mind windows can only recognize...4 giggs unless its 64 bit vista..128+....

    I bought 8 giggs at best buy for 800 usd.. and loaded it into my 32 bit..system, the motherboard recognizes it but the OS doesn't, there isn't enough support for 64 bit computing just yet...

    unless you have custom software...
  7. Crucial lists DDR2-800 @2.2v as an option for my D9200.

    The DDR2-667 that installed now is running at 1.8v.

    With no voltage adjustment on Dell mobo, how does the 800 work out? Does the mobo run the 800, but steps it down to 667?
  8. Quite possible.
  9. You can use 2.2v, the dell MB will just run it at 1.8v 800MHz. (2.2v means it can run higher than the standard 1.8v but it still must work correctly at 1.8v, 2.2v just gives you room to overclock.)

    As far as I know, if you're mixing 667Mhz with 800Mhz, it will all run at 667Mhz.

    $800 for 8gigs of 800Mhz ram is way too much. You can get the same for $140 at newegg.
  10. Here's screenshot of gnome's software run on my T-3400. I have the 800 ddr2 Ram.

    #10     Mar 26, 2008