Please report all spam threads, posts and suspicious members. We receive spam notifications and will take immediate action!
Results 1 to 3 of 3

Thread: FSB vs. CPU speed - why the rush for higher FSB?




  1. #1
    Chike is offline Senior Member
    Join Date
    Jun 2009
    Location
    Israel
    Posts
    6,531

    Default FSB vs. CPU speed - why the rush for higher FSB?

    This is a an educational question by it's nature.

    I ask this because I see many people pushing their FSB up while compromising CPU speed.
    There are several reasons I can understand for doing so:
    a. The CPU cannot overclock above certain speed.
    b. The CPU cooling is exhusted, or you just want lower CPU temperatures.
    c. You want to run at highest FSB possible.

    For the first two reason you would (possibly) get higher memory bandwidth and lower latencies which some application would benefit from. The third, while not being rational, is still acceptable.

    But does it make sence to have a lower seepd and higher FSB for practical reasons?
    If you have a CPU that is capable of doing 4.5GHz with 450FSB is there any practical reason to run it at 4.25GHz with 500FSB, other than those mentioned above?
    Would benchmarks (ther than memory benchmarks) show any gain, and what benchmarks if there are?

  2. #2
    Join Date
    Jul 2009
    Posts
    25

    Default Re: FSB vs. CPU speed - why the rush for higher FSB?

    I played around with this with my opteron X2,

    I found for 99% of what I cpu speed > *

  3. #3
    Join Date
    Apr 2009
    Location
    J'Habite En Angleterre
    Posts
    2,431

    Default Re: FSB vs. CPU speed - why the rush for higher FSB?

    There don't seem to be many gimping CPU speed over FSB, rather they're finding the max FSB within the range of max CPU.

    Good benchmarks that care about FSB include the usual RAM tests, plus things like SuperPI.

    Anything else that heavily relies on the FSB will benefit, including but not limited to video encoding/transcoding, audio work, encryption, compression/decompression and also some real world apps and games.

    As always, test your config. If getting 425*8 vs 400*8.5, the higher FSB would be better. Choosing 425*8 over 400*9 though, would likely be counter productive.

    As D-an-W, grishkafool and BoombasticSloth have done, maxing CPU vs FSB to within ~100MHz of max CPU speed is best. I'm sure they've all tried for the highest FSB they can, but not for 24/7 I'd imagine, just for kicks.

    In your case, 420*8 may give slightly better performance, but only if you can run the RAM at a similar speed. Some FSB's take you out of range of ideal RAM multi settings which means that even a higher FSB and CPU clock can perform poorer in some cases.
    Coolermaster CM 690 II advance Case
    Corsair HX750 (CWT, 91%(80+ Gold rated @230V) single 62A 12V rail
    P55A-UD4 v2.0 @ F14
    Core i5 760 @ 20 x 201, 4.02GHz
    TRUE Black with a single Noctua NF-P12 pumping out 55 CFM @ 19db .
    2 x 2GB Mushkin Ridgeback (996902), @ 7-10-8-27, 2010-DDR, 1.66v
    2 x Gigabyte GTX 460 1024MB in SLI (Pre OC'd to 715MHz core and 1800MHz VRAM) @ 850 Core / 4100 Mem.
    Intel X25-M Boot Drive (OS and Programs) 200MB/s Read & 90MB/s Write
    Corsair X32 200MB/s Read & 100MB/s Write
    WD Caviar Blue 640GB C (Steam, Games, Storage, Temp Files & Folders, etc)
    Samsung F3 500GB Backup/Images
    Noctua 1300RPM 19dB case fan (rear extraction)
    3 x 140 MM Coolermaster LED fans (one front intake, one top extraction, one side intake)
    Dell Ultra Sharp 2209WAf E-IPS @ 1680x1050

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •