Dual/Quad Channel speeds

Discussion in 'Mac Pro' started by Transeau, Nov 26, 2006.

  1. Transeau macrumors 6502a

    Transeau

    Joined:
    Jan 18, 2005
    Location:
    Alta Loma, CA
    #1
    I decided to play a bit this afternoon. I wanted to see the throughput differences with various memory configurations.

    Before you post and flame me... I AM NOT TRYING TO SELL YOU ON A SPECIFIC CONFIGURATION. I'm just posting the averaged results to my tests.

    Each configuration was tested 10 times and the score was averaged. The tests were done in Single User mode, CLI only. No Networking, GUI, services... nothing.

    Config 1: 2x 512MB, Apple OEM
    Geekbench Score: 363

    Config 2: 4x 512MB, Apple OEM, All DIMMs on Riser 1
    Score: 359

    Config 3: 4x 512MB, Apple OEM, 2x Riser 1, 2x Riser 2
    Score: 418


    Config 4: 2x 1GB, Dell OEM
    Geekbench Score: 359

    Config 5: 4x 1GB, Dell OEM, All DIMMs on Riser 1
    Score: 357

    Config 6: 4x 1GB, Dell OEM, 2x Riser 1, 2x Riser 2
    Score: 421


    Config 7: 2x 512MB, Apple OEM, 2x 1GB Dell OEM, 2x Riser 1, 2x Riser 2
    Geekbench Score: 347

    Config 8: 2x 512MB, Apple OEM, 2x 1GB Dell OEM, All DIMMs on Riser 1
    Score: 358

    Config 9: 4x 512MB, Apple OEM, 4x 1GB, Dell OEM, 2x2 Riser 1, 2x2 Riser 2
    Score: 411

    Config 10: 4x 1GB Dell OEM (2x R1, 2X R2), 2x 512MB Apple OEM (2x R1)
    Score: 361

    My best result came from 4x 1GB DIMMs, configured in DIMM1/2 on each riser. The console in rEFIt confirms this is Quad Channel. The worst result was 2x 1GB on Riser 1 and 2x 512MB on Riser 2. The console confirmed that this is dual channel.

    The results were not as dramatic as I expected. I did expect closer to 2x the throughput between Dual and Quad channel mode. There is an improvement of about 18%, and this will show up in memory intense apps. I think the increase would be more if the benchmark used larger blocks of data.
     
  2. Ozy macrumors regular

    Ozy

    Joined:
    Aug 8, 2006
    Location:
    Goodyear, AZ
    #2
    Thanks for your tests. I am picking up my Mac Pro today and also getting another 4GB (4x1GB). This will allow 5GB total (2x512MB OEM, 4x1GB OEM). What configuration do you recommend to maintain quad channel performance?

    Thx
     
  3. Transeau thread starter macrumors 6502a

    Transeau

    Joined:
    Jan 18, 2005
    Location:
    Alta Loma, CA
    #3
    If you really need the extra speed, you will need to loose the 2 512's or pick up two more 512's.
     
  4. tyr2 macrumors 6502a

    tyr2

    Joined:
    May 6, 2006
    Location:
    Leeds, UK
    #4
    Interesting results, thanks.

    You might also be interested in these application benchmarks that Anandtech did between dual/quad channel.
     

Share This Page