Page 1 of 2 12 LastLast
Results 1 to 16 of 23

Thread: DDR2 RAM Speeds

  1. #1
    Senior Member
    Join Date
    Jul 2003
    Posts
    11,038
    Thanks
    682
    Thanked
    388 times in 271 posts

    DDR2 RAM Speeds

    How does the DDR2/PC2.... speed compair to the FSB of the CPU.
    Reason I ask is theres some pretty fast ram out there but what's actually needed and whats overkill...
    Looking at RAM for an Intel 6400

  2. #2
    Hardcore Til I Die htid's Avatar
    Join Date
    Mar 2006
    Location
    London
    Posts
    1,802
    Thanks
    81
    Thanked
    32 times in 22 posts
    • htid's system
      • Motherboard:
      • Asus P5B
      • CPU:
      • C2D E6600 @ 3ghz
      • Memory:
      • 2gb Corsair XMS2
      • Storage:
      • 180gb Spinpoint
      • Graphics card(s):
      • XFX 7900GTX
      • PSU:
      • 500W Seasonic S12
      • Case:
      • Akasa Mirage
      • Monitor(s):
      • 18" Dell
    I'll copy what i posted to someone else yesterday

    From my limited knowledge of overclocking, your ram clock speed needs to be double your fsb speed (hope that's right). Since PC5300 is 667mhz half that is 333.5, and 333.5 x 9 (the multiplier on an E6600...not sure about the E6300) is around 3ghz so theoretically i would assume you can get 3ghz with that RAM, but you should definitely be able to overclock, just depends how high

    (I may be talking crap here, so if I am can somebody please tell me or i'll never learn )

    -----------

    Dunno what the multi on an 6400 is so you'll have to find that out yourself but the premise is the same.

    Hope that helps!
    Last edited by htid; 16-11-2006 at 05:59 PM.

  3. #3
    Hardcore Til I Die htid's Avatar
    Join Date
    Mar 2006
    Location
    London
    Posts
    1,802
    Thanks
    81
    Thanked
    32 times in 22 posts
    • htid's system
      • Motherboard:
      • Asus P5B
      • CPU:
      • C2D E6600 @ 3ghz
      • Memory:
      • 2gb Corsair XMS2
      • Storage:
      • 180gb Spinpoint
      • Graphics card(s):
      • XFX 7900GTX
      • PSU:
      • 500W Seasonic S12
      • Case:
      • Akasa Mirage
      • Monitor(s):
      • 18" Dell
    double post

  4. #4
    Anthropomorphic Personification shaithis's Avatar
    Join Date
    Apr 2004
    Location
    The Last Aerie
    Posts
    10,857
    Thanks
    645
    Thanked
    872 times in 736 posts
    • shaithis's system
      • Motherboard:
      • Asus P8Z77 WS
      • CPU:
      • i7 3770k @ 4.5GHz
      • Memory:
      • 32GB HyperX 1866
      • Storage:
      • Lots!
      • Graphics card(s):
      • Sapphire Fury X
      • PSU:
      • Corsair HX850
      • Case:
      • Corsair 600T (White)
      • Operating System:
      • Windows 10 x64
      • Monitor(s):
      • 2 x Dell 3007
      • Internet:
      • Zen 80Mb Fibre
    If you need to figure out the maximum rated speed for the RAM, just divide the PCxxxxx number by 8.

    That gives you the max speed but because its double data rate, you then divide by 2 again to get the 'FSB value'...
    Main PC: Asus Rampage IV Extreme / 3960X@4.5GHz / Antec H1200 Pro / 32GB DDR3-1866 Quad Channel / Sapphire Fury X / Areca 1680 / 850W EVGA SuperNOVA Gold 2 / Corsair 600T / 2x Dell 3007 / 4 x 250GB SSD + 2 x 80GB SSD / 4 x 1TB HDD (RAID 10) / Windows 10 Pro, Yosemite & Ubuntu
    HTPC: AsRock Z77 Pro 4 / 3770K@4.2GHz / 24GB / GTX 1080 / SST-LC20 / Antec TP-550 / Hisense 65k5510 4K TV / HTC Vive / 2 x 240GB SSD + 12TB HDD Space / Race Seat / Logitech G29 / Win 10 Pro
    HTPC2: Asus AM1I-A / 5150 / 4GB / Corsair Force 3 240GB / Silverstone SST-ML05B + ST30SF / Samsung UE60H6200 TV / Windows 10 Pro
    Spare/Loaner: Gigabyte EX58-UD5 / i950 / 12GB / HD7870 / Corsair 300R / Silverpower 700W modular
    NAS 1: HP N40L / 12GB ECC RAM / 2 x 3TB Arrays || NAS 2: Dell PowerEdge T110 II / 24GB ECC RAM / 2 x 3TB Hybrid arrays || Network:Buffalo WZR-1166DHP w/DD-WRT + HP ProCurve 1800-24G
    Laptop: Dell Precision 5510 Printer: HP CP1515n || Phone: Huawei P30 || Other: Samsung Galaxy Tab 4 Pro 10.1 CM14 / Playstation 4 + G29 + 2TB Hybrid drive

  5. #5
    Senior Member
    Join Date
    Jul 2004
    Location
    Probably Poole
    Posts
    386
    Thanks
    0
    Thanked
    5 times in 5 posts
    • Hottentot's system
      • Motherboard:
      • Asus P5Q Pro
      • CPU:
      • Q9550 at 3.8 GHz
      • Memory:
      • 8 GB
      • Storage:
      • SSD + HDD
      • Graphics card(s):
      • ATI 7950
      • PSU:
      • Corsair 650TX
      • Case:
      • CM HAF 932 (watercooled)
      • Operating System:
      • Windows 7 (x64)
      • Monitor(s):
      • NEC 2690WUXi
      • Internet:
      • Virgin 10Mb
    Multiplier on the 6400 is 8.
    Default bus speed is 266 which is DDR2 4200 (533MHz)
    8 x 266 = 2.13 GHz

    If you put DDR2 6400 (800MHz) in and ran 1:1
    8 x 400 = 3.2GHz

    Intel boards don't let you run the memory slower than the FSB so you need fast memory. The new Nvidia and ATI boards will let you run the memory slower so fast memory is not important.

  6. #6
    Senior Member
    Join Date
    Jul 2006
    Posts
    207
    Thanks
    0
    Thanked
    0 times in 0 posts
    • Hidden Hippo's system
      • Motherboard:
      • Gigabyte Z68AP-D3
      • CPU:
      • i5 2500k (stock)
      • Memory:
      • 8GB Corsair Ballistix 1600MHz
      • Storage:
      • 250GB WD Caviar
      • Graphics card(s):
      • HD4870 1GB
      • PSU:
      • Tagan TG530-U15 530W
      • Case:
      • Thermaltake Armour
      • Operating System:
      • Windows 7 64-bit
      • Monitor(s):
      • BenQ FP241W
    The AB9 series boards do support a 4:5 and 2:3 divider on the memory, so you are able to run 800MHz memory on the stock FSB. I myself am running my E6600 at 267 with a 2:3 ration for 800MHz.

  7. #7
    Senior Member
    Join Date
    Jul 2003
    Posts
    11,038
    Thanks
    682
    Thanked
    388 times in 271 posts
    Quote Originally Posted by Hottentot View Post
    Multiplier on the 6400 is 8.
    Default bus speed is 266 which is DDR2 4200 (533MHz)
    8 x 266 = 2.13 GHz

    If you put DDR2 6400 (800MHz) in and ran 1:1
    8 x 400 = 3.2GHz

    Intel boards don't let you run the memory slower than the FSB so you need fast memory. The new Nvidia and ATI boards will let you run the memory slower so fast memory is not important.
    The 6400 tho states 1066Mhz FSB or is that just the quad pumped intel tosh

  8. #8
    Senior Member
    Join Date
    Jul 2004
    Location
    Probably Poole
    Posts
    386
    Thanks
    0
    Thanked
    5 times in 5 posts
    • Hottentot's system
      • Motherboard:
      • Asus P5Q Pro
      • CPU:
      • Q9550 at 3.8 GHz
      • Memory:
      • 8 GB
      • Storage:
      • SSD + HDD
      • Graphics card(s):
      • ATI 7950
      • PSU:
      • Corsair 650TX
      • Case:
      • CM HAF 932 (watercooled)
      • Operating System:
      • Windows 7 (x64)
      • Monitor(s):
      • NEC 2690WUXi
      • Internet:
      • Virgin 10Mb
    Yes that is the quad pumped tosh. It was easier back in the old days when memory was described by its speed which matched up with the motherboards FSB.
    Its a choice now between an expensive mobo (£200) which will let you run with asynch slower memory or buying expensive fast memory. Tricky

  9. #9
    its all clear now
    Join Date
    Jul 2006
    Posts
    1,251
    Thanks
    60
    Thanked
    19 times in 17 posts
    • No.72's system
      • Motherboard:
      • commando
      • CPU:
      • e6300 3.50ghz artic 7
      • Memory:
      • 4gb corsair red tracers
      • Storage:
      • 320gb RAID0
      • Graphics card(s):
      • 4870XT
      • PSU:
      • 620 watt corsair
      • Case:
      • coolmaster 831 SE orange
      • Monitor(s):
      • 2407WFP AO4
      • Internet:
      • 10 meg virgin
    way hay what part of poole?

  10. #10
    Senior Member
    Join Date
    Jul 2004
    Location
    Probably Poole
    Posts
    386
    Thanks
    0
    Thanked
    5 times in 5 posts
    • Hottentot's system
      • Motherboard:
      • Asus P5Q Pro
      • CPU:
      • Q9550 at 3.8 GHz
      • Memory:
      • 8 GB
      • Storage:
      • SSD + HDD
      • Graphics card(s):
      • ATI 7950
      • PSU:
      • Corsair 650TX
      • Case:
      • CM HAF 932 (watercooled)
      • Operating System:
      • Windows 7 (x64)
      • Monitor(s):
      • NEC 2690WUXi
      • Internet:
      • Virgin 10Mb
    Parkstone

  11. #11
    Member
    Join Date
    Dec 2005
    Posts
    174
    Thanks
    9
    Thanked
    4 times in 3 posts
    Quote Originally Posted by Hottentot View Post
    Intel boards don't let you run the memory slower than the FSB
    Im sure that it can run slower or faster with dividers otherwise you would be stuck if you had slower ram

  12. #12
    its all clear now
    Join Date
    Jul 2006
    Posts
    1,251
    Thanks
    60
    Thanked
    19 times in 17 posts
    • No.72's system
      • Motherboard:
      • commando
      • CPU:
      • e6300 3.50ghz artic 7
      • Memory:
      • 4gb corsair red tracers
      • Storage:
      • 320gb RAID0
      • Graphics card(s):
      • 4870XT
      • PSU:
      • 620 watt corsair
      • Case:
      • coolmaster 831 SE orange
      • Monitor(s):
      • 2407WFP AO4
      • Internet:
      • 10 meg virgin
    O nice I am from parkstone! where about in parkstone?

  13. #13
    Senior Member
    Join Date
    Jul 2003
    Posts
    11,038
    Thanks
    682
    Thanked
    388 times in 271 posts
    So for the new Intel 1066Mhz chips you need PC2-8500+ then...

    Bet thats not cheap then...

  14. #14
    Resident abit mourner BUFF's Avatar
    Join Date
    Jul 2003
    Location
    Sunny Glasgow
    Posts
    8,067
    Thanks
    7
    Thanked
    181 times in 171 posts
    Quote Originally Posted by [GSV]Trig View Post
    So for the new Intel 1066Mhz chips you need PC2-8500+ then...
    no, you don't.
    DDR2-8500 is 533fsb but Intel's 1066 is really 266 quad pumped so for stock operation even DDR2-4200 is fine (there are actually chipsets that will run 1066MHz chips using DDR400).

    MSI P55-GD80, i5 750
    abit A-S78H, Phenom 9750,

    My HEXUS.trust abit forums

  15. #15
    Banhammer in peace PeterB kalniel's Avatar
    Join Date
    Aug 2005
    Posts
    29,863
    Thanks
    1,623
    Thanked
    3,053 times in 2,476 posts
    • kalniel's system
      • Motherboard:
      • Gigabyte Z390 Aorus Ultra
      • CPU:
      • Intel i9 9900k
      • Memory:
      • 32GB DDR4 3200 CL16
      • Storage:
      • 1TB Samsung 970Evo+ NVMe
      • Graphics card(s):
      • nVidia GTX 1060 6GB
      • PSU:
      • Seasonic 600W
      • Case:
      • Cooler Master HAF 912
      • Operating System:
      • Win 10 Pro x64
      • Monitor(s):
      • Dell U2311H
      • Internet:
      • rubbish
    Some notes on speeds:

    Core 2 Duo motherboards all have to support 1066 fsb. This is not the real fsb (front side bus) speed, but the speed of the connection to the CPU. In intels case they quad pump the real fsb for the connection to the CPU. 1066 is 4x the real fsb of 266.

    The CPU speed works in multiples of the real fsb, so a 2.66ghz chip is using a 10x multiplier.

    Ram also normally works at this same speed of 266mhz, but in the case of DDR (double data rate) RAM manufacturer's quote speeds at double the real speed, because they are transfering twice as much information per cycle.

    Therefore we can conclude that at 'normal' settings, the RAM has to be 533mhz, and the motherboard has to be 1066mhz, to support Core 2 Duo.

    Things get interesting when you either overclock or change the ram:fsb speed ratio. Overclocking can be done one of two ways - increasing the multiplier (ie go for 11x266 instead of 10x) or changing the fsb (going for 10x300 instead of 10x266). Extreme processors allow multipliers to be changed, but it is fixed for non-extreme models, leaving fsb as the only way to improve things.

    Most motherboards these days allow a lot of head room for increasing fsb. They often do this by clamping the speed that other components talk to the fsb - so your graphics card still communicate at the normal speed for example. However if you are still running the ram at 1:1 with the fsb you have to make sure your ram is rated at higher speeds. DDR2 800 (real speed = 400mhz) gives a ridiculous amount of headroom for increased fsb, infact your motherboard will likely fail before you reach this speed. So how do you take advantage of this extra speed?

    You run the RAM at a different speed to the FSB.

    In earlier CPUs running the ram asynchronously gave a performance penalty, but with the new generation of chips this is no longer the case. That means you can run your FSB:RAM at 4:5 ratio for example, letting you run 266 fsb but ram running at 333 mhz. Then you can overclock the fsb on top, but as the rams running faster you don't need to overclock as much to get the most out of the ram potential.

  16. #16
    Anthropomorphic Personification shaithis's Avatar
    Join Date
    Apr 2004
    Location
    The Last Aerie
    Posts
    10,857
    Thanks
    645
    Thanked
    872 times in 736 posts
    • shaithis's system
      • Motherboard:
      • Asus P8Z77 WS
      • CPU:
      • i7 3770k @ 4.5GHz
      • Memory:
      • 32GB HyperX 1866
      • Storage:
      • Lots!
      • Graphics card(s):
      • Sapphire Fury X
      • PSU:
      • Corsair HX850
      • Case:
      • Corsair 600T (White)
      • Operating System:
      • Windows 10 x64
      • Monitor(s):
      • 2 x Dell 3007
      • Internet:
      • Zen 80Mb Fibre
    Most boards now let you set multipliers BELOW the CPUs default.
    Main PC: Asus Rampage IV Extreme / 3960X@4.5GHz / Antec H1200 Pro / 32GB DDR3-1866 Quad Channel / Sapphire Fury X / Areca 1680 / 850W EVGA SuperNOVA Gold 2 / Corsair 600T / 2x Dell 3007 / 4 x 250GB SSD + 2 x 80GB SSD / 4 x 1TB HDD (RAID 10) / Windows 10 Pro, Yosemite & Ubuntu
    HTPC: AsRock Z77 Pro 4 / 3770K@4.2GHz / 24GB / GTX 1080 / SST-LC20 / Antec TP-550 / Hisense 65k5510 4K TV / HTC Vive / 2 x 240GB SSD + 12TB HDD Space / Race Seat / Logitech G29 / Win 10 Pro
    HTPC2: Asus AM1I-A / 5150 / 4GB / Corsair Force 3 240GB / Silverstone SST-ML05B + ST30SF / Samsung UE60H6200 TV / Windows 10 Pro
    Spare/Loaner: Gigabyte EX58-UD5 / i950 / 12GB / HD7870 / Corsair 300R / Silverpower 700W modular
    NAS 1: HP N40L / 12GB ECC RAM / 2 x 3TB Arrays || NAS 2: Dell PowerEdge T110 II / 24GB ECC RAM / 2 x 3TB Hybrid arrays || Network:Buffalo WZR-1166DHP w/DD-WRT + HP ProCurve 1800-24G
    Laptop: Dell Precision 5510 Printer: HP CP1515n || Phone: Huawei P30 || Other: Samsung Galaxy Tab 4 Pro 10.1 CM14 / Playstation 4 + G29 + 2TB Hybrid drive

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Fast RAM or More RAM?
    By stephent3 in forum PC Hardware and Components
    Replies: 25
    Last Post: 06-03-2006, 06:38 PM
  2. Asus AV8 and 2Gb RAM ...Frequency Drop
    By cptwhite_uk in forum PC Hardware and Components
    Replies: 7
    Last Post: 27-04-2005, 04:49 AM
  3. Finally got some RAM, TCCD no less...
    By Scarlet Infidel in forum PC Hardware and Components
    Replies: 12
    Last Post: 16-04-2005, 02:29 PM
  4. What should I do about my RAM?
    By spindle in forum PC Hardware and Components
    Replies: 2
    Last Post: 20-03-2004, 02:44 PM

Posting Permissions

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