Overclock.net › Forums › Intel › Intel CPUs › Importance of FSB: DRAM Ratio
New Posts  All Forums:Forum Nav:

Importance of FSB: DRAM Ratio

post #1 of 10
Thread Starter 
ok, what's the deal with this? In the past there has been plenty of speculation about performance enhancement/efficency by keeping the FSB: DRAM ratio 1:1.

I've posted my speculation on this in other threads in the past and for the most part in hopes that someone would argue with me. That someone would say, "no.. that's not true and here's why...". Unfortunately it hasn't happened and I haven't posted a specific thread inquiring about it in the past because the gains in CPU speed were very minimal and it was simply easier for me to choose to go back down 50MHz or so on the CPU to keep the 1:1 ratio

Now, with the E8600, I am more concerned about this. I am actually having a bit of trouble attaining the OC's that many people on overclock.net have and most fingers are pointed at my old 650i chipset.

However, a few (not many) people have suggested that I keep my memory at 800MHz (I use PC6400) and keep bumping my FSB speed to squeeze out as much as I can on the CPU. I stand to pick up about 400MHz by doing this....although I have not been stable at 4.4GHz yet. Am trying... may replace my mobo or my memory, not sure yet.


Anyway, what I am really looking for here is some insight, some informed opinion, on the actual importance of the FSB: DRAM 1:1 ratio. Please note... I am only looking for informed/experienced opinion on this. Not speculation that can't be backed up with actual data or a convincing logical explanation.
    
CPUMotherboardGraphicsRAM
Intel Core i5-3570K Ivy Bridge ASUS SABERTOOTH Z77 eVGA GTX560 SSC (Fermi) G.SKILL Ripjaws Series 8GB (2 x 4GB)  
Hard DriveHard DriveOSMonitor
3x 1TB Western Digital SATA 7200rpm OCZ Agility 3 120GB SSD Windows 7 Ultimate x64 Sceptre 24" WS @ 1920x1200, 4ms 
KeyboardPowerCaseMouse
Logitech G11 Corsair 750TX 750w +12V@60A Antec 900 Logitech MX 518 
Audio
Creative SB Live 24-bit 
  hide details  
Reply
    
CPUMotherboardGraphicsRAM
Intel Core i5-3570K Ivy Bridge ASUS SABERTOOTH Z77 eVGA GTX560 SSC (Fermi) G.SKILL Ripjaws Series 8GB (2 x 4GB)  
Hard DriveHard DriveOSMonitor
3x 1TB Western Digital SATA 7200rpm OCZ Agility 3 120GB SSD Windows 7 Ultimate x64 Sceptre 24" WS @ 1920x1200, 4ms 
KeyboardPowerCaseMouse
Logitech G11 Corsair 750TX 750w +12V@60A Antec 900 Logitech MX 518 
Audio
Creative SB Live 24-bit 
  hide details  
Reply
post #2 of 10
After extensive benchmarking in the past couple of years, I have seen no huge benefit in running 1:1. Now I usually just set the FSB to obtain the cpu speed that I'm after and then choose the memory speed that most closely matches the stock frequency unless I'm trying to squeeze a few more 3dmarks out of the setup by OC'ing the memory.
post #3 of 10
I think this was more prevelant with DDR not DDR2, especially with timings getting so loose. Back in the day 2T was unheard of and we all felt it would just crap out our performance even with a high mhz. I generally keep my ram at its stock speed and concentrate more on achieving a higher FSB on my CPU.

I used to have your board but just had a ***** of a time with voltage and achieving a FSB on could live with.

pink
post #4 of 10
Rob you have peaked my curiosity. So watch out for the rambling.

There is no inherent value in a 1:1 vs 2:3 other than at the same FSB it would be faster?

Oh other than the latency? That is the wrinkle or the wrench in the equation.

You must take both into consideration. If lower speed allows you to tighten timings it could offer equal or better performance. Regardless of overall clock speeds.

You cannot separate one from the other. Also on a further note there is no true synchronization which likely is one of the theoretical advantages of 1:1 but it just does not happen.

Edit: Mr Pink makes a very good point about how back in the past with tighter timings it might of mattered. But with our very high timings and very high clocks out the window so to speak.
Edited by Asus Mobile - 2/14/09 at 6:56pm
    
CPUMotherboardGraphicsRAM
T9400 2.53Ghz OC 2.85Ghz Asus ATI Mobility Radeon HD 3650 OC 780/500 4GB PC2-6400 OC 900Mhz 
Hard DriveOSMonitor
WD 320GB @5400 Vista 32bit Home Premium 14" WXGA+ 
  hide details  
Reply
    
CPUMotherboardGraphicsRAM
T9400 2.53Ghz OC 2.85Ghz Asus ATI Mobility Radeon HD 3650 OC 780/500 4GB PC2-6400 OC 900Mhz 
Hard DriveOSMonitor
WD 320GB @5400 Vista 32bit Home Premium 14" WXGA+ 
  hide details  
Reply
post #5 of 10
Quote from Driver heavan, Now the guy doesn't explain how he did his testing but this what he found:

Quote:
I've been playing around with some bios settings and have noticed something very interesting. Being told that 1:1 is the best way to OC ones fsb and ram I was very surprised. Anyways these are some settings and numbers I got from Everest.

430MHz fsb - 430MHz ram(860) - 3.44GHz cpu clock (1:1)
Memory Read- 7498MB/s
Memory Latency - 70.9ns

430MHz fsb - 516MHz ram(1032) - 3.44GHz cpu clock (5:6)
Memory Read - 8986MB/s
Memory Latency - 54.2ns

While I can somewhat understand the higher bandwidth -its still higher than I thought it would be- I was very surprised by the reduced latency. I honestly thought that 1:1 would provide the absolute lowest latency due to working in harmony but I was very wrong. The above may not seem as much but its a noticeable improvement all around. Anyways, I thought I would share my findings for those with the same mindset as the improvement is worthy
They also mention this arcticle saying offers some insite into the matter:

http://www.anandtech.com/mb/showdoc.aspx?i=3208&p=4

Edit; Personally I run my ram unlocked because on Core 2 the memory controller is not on the CPU and therefore bandwidth is a big issue(on Core i7 on the otherhand where the controller is on the CPU latency is more important). I'm trying to find an arcticle which talks about this for you
Edited by Starbuck5000 - 2/14/09 at 7:13pm
    
CPUMotherboardGraphicsRAM
W3540 Asus P6X58D - Premium Asus GTX 480 12GB of Hypers 
Hard DriveOptical DriveOSMonitor
Kingston 128GB,2xRAID0 VRaptors, 320GB Backup LG Blu-Ray Drive, Generic DVD-RW drive Windows 7 Pro 1xDell P2310H 1xDell U2311H 
KeyboardPowerCaseMouse
Dell Multimedia USB Corsair TX850W Fractal Design Define XL G5 
Mouse Pad
Pedo-Bear mousemat 
  hide details  
Reply
    
CPUMotherboardGraphicsRAM
W3540 Asus P6X58D - Premium Asus GTX 480 12GB of Hypers 
Hard DriveOptical DriveOSMonitor
Kingston 128GB,2xRAID0 VRaptors, 320GB Backup LG Blu-Ray Drive, Generic DVD-RW drive Windows 7 Pro 1xDell P2310H 1xDell U2311H 
KeyboardPowerCaseMouse
Dell Multimedia USB Corsair TX850W Fractal Design Define XL G5 
Mouse Pad
Pedo-Bear mousemat 
  hide details  
Reply
post #6 of 10
Thread Starter 
Asus_Mobile, I'm glad I piqued your curiosity, however, your response almost in its entirety is what I am trying to avoid in this thread. For what its worth, I mean absolutely no offense by that. Your post says absolutely nothing though.
    
CPUMotherboardGraphicsRAM
Intel Core i5-3570K Ivy Bridge ASUS SABERTOOTH Z77 eVGA GTX560 SSC (Fermi) G.SKILL Ripjaws Series 8GB (2 x 4GB)  
Hard DriveHard DriveOSMonitor
3x 1TB Western Digital SATA 7200rpm OCZ Agility 3 120GB SSD Windows 7 Ultimate x64 Sceptre 24" WS @ 1920x1200, 4ms 
KeyboardPowerCaseMouse
Logitech G11 Corsair 750TX 750w +12V@60A Antec 900 Logitech MX 518 
Audio
Creative SB Live 24-bit 
  hide details  
Reply
    
CPUMotherboardGraphicsRAM
Intel Core i5-3570K Ivy Bridge ASUS SABERTOOTH Z77 eVGA GTX560 SSC (Fermi) G.SKILL Ripjaws Series 8GB (2 x 4GB)  
Hard DriveHard DriveOSMonitor
3x 1TB Western Digital SATA 7200rpm OCZ Agility 3 120GB SSD Windows 7 Ultimate x64 Sceptre 24" WS @ 1920x1200, 4ms 
KeyboardPowerCaseMouse
Logitech G11 Corsair 750TX 750w +12V@60A Antec 900 Logitech MX 518 
Audio
Creative SB Live 24-bit 
  hide details  
Reply
post #7 of 10
Quote:
Originally Posted by r0b126 View Post
Asus_Mobile, I'm glad I piqued your curiosity, however, your response almost in its entirety is what I am trying to avoid in this thread. For what its worth, I mean absolutely no offense by that. Your post says absolutely nothing though.
No problem and no offense taken. To talk about a 1:1 ratio as having magical traits ignoring timings is less than complete but good luck in getting an answer, you might.
    
CPUMotherboardGraphicsRAM
T9400 2.53Ghz OC 2.85Ghz Asus ATI Mobility Radeon HD 3650 OC 780/500 4GB PC2-6400 OC 900Mhz 
Hard DriveOSMonitor
WD 320GB @5400 Vista 32bit Home Premium 14" WXGA+ 
  hide details  
Reply
    
CPUMotherboardGraphicsRAM
T9400 2.53Ghz OC 2.85Ghz Asus ATI Mobility Radeon HD 3650 OC 780/500 4GB PC2-6400 OC 900Mhz 
Hard DriveOSMonitor
WD 320GB @5400 Vista 32bit Home Premium 14" WXGA+ 
  hide details  
Reply
post #8 of 10
Running your memory faster then your FSB does gain some speed. But if you have 800mhz @ CL4, you must at least get 1000mhz @ CL5 to get some profit out of it.

A long time ago I tested some sets @ 800mhz and then @ 1200mhz in 3Dmark '01, the difference was like 4500 points in favor of the 1200mhz DDR2.
Money dump
(15 items)
 
  
CPUMotherboardGraphicsRAM
Core i5 3570k 4.0Ghz Asus P8Z77-V Pro Sapphire HD7870XT Dual-X 2GB Samsung Green 8GB 1600 @ 1866 
Hard DriveOptical DriveCoolingOS
Samsung 830 128GB SSD, Seagate 3TB, Samsung 1TB Sony DVD/Rw 24x Thermalright Ultra 120 Extreme Windows 8.1 Pro 
MonitorKeyboardPowerCase
Dell UltraSharp U2311H Saitek Eclipse II Seasonic X-650 Antec P183 
MouseAudio
Steelseries Xai Asus Xonar D1 / M-Audio AV40 / Ultrasone HFI-650 
  hide details  
Reply
Money dump
(15 items)
 
  
CPUMotherboardGraphicsRAM
Core i5 3570k 4.0Ghz Asus P8Z77-V Pro Sapphire HD7870XT Dual-X 2GB Samsung Green 8GB 1600 @ 1866 
Hard DriveOptical DriveCoolingOS
Samsung 830 128GB SSD, Seagate 3TB, Samsung 1TB Sony DVD/Rw 24x Thermalright Ultra 120 Extreme Windows 8.1 Pro 
MonitorKeyboardPowerCase
Dell UltraSharp U2311H Saitek Eclipse II Seasonic X-650 Antec P183 
MouseAudio
Steelseries Xai Asus Xonar D1 / M-Audio AV40 / Ultrasone HFI-650 
  hide details  
Reply
post #9 of 10
Thread Starter 
Quote:
Originally Posted by Starbuck5000 View Post
I'm trying to find an arcticle which talks about this for you
The hunt for it is tough... I know. I've done a lot of my own research as well, but haven't really found anything worth posting yet (nothing beneficial to readers here). I am not using this as a tact to get people to do my research for me, but the more willing the better. I am hoping this thread will prove useful to readers in the future. It may help avoid unnecessary headaches.


Acoma_Andy: That's quite a jump in memory speeds; 50%. Was that change made without any adjustment to the CPU clock speed? What was your FSB speed at the time? 800/1600 would be 1:1, 1200:1600 is 3:4...just making an assumption with the 1600 atm



I do appreciate all the responses and input thus far, please keep 'em coming
    
CPUMotherboardGraphicsRAM
Intel Core i5-3570K Ivy Bridge ASUS SABERTOOTH Z77 eVGA GTX560 SSC (Fermi) G.SKILL Ripjaws Series 8GB (2 x 4GB)  
Hard DriveHard DriveOSMonitor
3x 1TB Western Digital SATA 7200rpm OCZ Agility 3 120GB SSD Windows 7 Ultimate x64 Sceptre 24" WS @ 1920x1200, 4ms 
KeyboardPowerCaseMouse
Logitech G11 Corsair 750TX 750w +12V@60A Antec 900 Logitech MX 518 
Audio
Creative SB Live 24-bit 
  hide details  
Reply
    
CPUMotherboardGraphicsRAM
Intel Core i5-3570K Ivy Bridge ASUS SABERTOOTH Z77 eVGA GTX560 SSC (Fermi) G.SKILL Ripjaws Series 8GB (2 x 4GB)  
Hard DriveHard DriveOSMonitor
3x 1TB Western Digital SATA 7200rpm OCZ Agility 3 120GB SSD Windows 7 Ultimate x64 Sceptre 24" WS @ 1920x1200, 4ms 
KeyboardPowerCaseMouse
Logitech G11 Corsair 750TX 750w +12V@60A Antec 900 Logitech MX 518 
Audio
Creative SB Live 24-bit 
  hide details  
Reply
post #10 of 10
Thread Starter 
bump
    
CPUMotherboardGraphicsRAM
Intel Core i5-3570K Ivy Bridge ASUS SABERTOOTH Z77 eVGA GTX560 SSC (Fermi) G.SKILL Ripjaws Series 8GB (2 x 4GB)  
Hard DriveHard DriveOSMonitor
3x 1TB Western Digital SATA 7200rpm OCZ Agility 3 120GB SSD Windows 7 Ultimate x64 Sceptre 24" WS @ 1920x1200, 4ms 
KeyboardPowerCaseMouse
Logitech G11 Corsair 750TX 750w +12V@60A Antec 900 Logitech MX 518 
Audio
Creative SB Live 24-bit 
  hide details  
Reply
    
CPUMotherboardGraphicsRAM
Intel Core i5-3570K Ivy Bridge ASUS SABERTOOTH Z77 eVGA GTX560 SSC (Fermi) G.SKILL Ripjaws Series 8GB (2 x 4GB)  
Hard DriveHard DriveOSMonitor
3x 1TB Western Digital SATA 7200rpm OCZ Agility 3 120GB SSD Windows 7 Ultimate x64 Sceptre 24" WS @ 1920x1200, 4ms 
KeyboardPowerCaseMouse
Logitech G11 Corsair 750TX 750w +12V@60A Antec 900 Logitech MX 518 
Audio
Creative SB Live 24-bit 
  hide details  
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Intel CPUs
Overclock.net › Forums › Intel › Intel CPUs › Importance of FSB: DRAM Ratio