DRAM:FSB Ratio?
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halcyon
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Jtt, to further the subject, I've read a lot on this forum that going with a 1:1 ratio is best but I don't truly understand why. If my FSB is at 425Mhz and my RAM at @ 850Mhz why does that offer "Best performance" as opposed to my FSB being at 425Mhz and my RAM being at 1066Mhz? Could someone add some clarity or point to a link that does?
Broadlly speaking, if you can get your RAM to run faster changing your DRAM:FSB ratio, do it. There's no point in getting you memory to run slower than it could go.
The point is that sometimes, because your cpu does not have an unlocked multiplier, overclocking it means pushing your memory beyond its limits (the FSB has impacts on the cpu clock and memory clock).
In this situation you need to change your ratios in order to compensate a higher FSB: the ratio "neutralizes" the higher FSB on your memory.
Any way, when ever you can keep your ratio at 1:1. It's more efficent, for the synchronism is automatic between RAM and CPU. It also runs cooler, because you don't need a "mechanism" for the synchronization (it's just a metaphor of what really happens, but I guess it'll do...).
The point is that sometimes, because your cpu does not have an unlocked multiplier, overclocking it means pushing your memory beyond its limits (the FSB has impacts on the cpu clock and memory clock).
In this situation you need to change your ratios in order to compensate a higher FSB: the ratio "neutralizes" the higher FSB on your memory.
Any way, when ever you can keep your ratio at 1:1. It's more efficent, for the synchronism is automatic between RAM and CPU. It also runs cooler, because you don't need a "mechanism" for the synchronization (it's just a metaphor of what really happens, but I guess it'll do...).
Zorg
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- May 31, 2004
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The argument goes like this. There is very little real world benefit to raising the RAM speed on the core 2 architecture, assuming you don't have an Allendale with the small cache. So why bother driving the RAM hard and running the northbridge at other than a 1:1 multiplier, thereby increasing the heat of both needlessly. It's better to lower the multiplier of the CPU and attempt to achieve a 1:1 with the RAM at it's rated speed or to underclock the RAM to 1:1 and tighten the timings.
The 1:1 ratio really becomes an issue if the OC is unstable, because 1:1 more stable. If, let's say, you want to run a Q6600 at 3.0G and you have DDR2 800 then your only choices are 1333 (333)/800 or 1333 (333)/667 with tighter timings. There is very little difference between these to options in real world apps, and the RAM and northbridge don't really get too hot. So either way is roughly the same.
If you can it is better, obviously, to lower the CPU multiplier to 8 and raise the FSB to 1600 (400) and run the CPU at 3.2G with the RAM at 800 1:1.
If you have DDR2 1066 and a CPU that is running at 1333, then it makes sense to lower the RAM to 800 and tighten the timings and thereby lower the temps even though it's not 1:1 because the additional real world performance is negligible.
Additionally you could try 667 with even tighter timings at 1:1, but IMO the heat is no longer an issue at that point.
Many do not agree with me and really like the 1:1 ratio and tighter timings over all else.
The 1:1 ratio really becomes an issue if the OC is unstable, because 1:1 more stable. If, let's say, you want to run a Q6600 at 3.0G and you have DDR2 800 then your only choices are 1333 (333)/800 or 1333 (333)/667 with tighter timings. There is very little difference between these to options in real world apps, and the RAM and northbridge don't really get too hot. So either way is roughly the same.
If you can it is better, obviously, to lower the CPU multiplier to 8 and raise the FSB to 1600 (400) and run the CPU at 3.2G with the RAM at 800 1:1.
If you have DDR2 1066 and a CPU that is running at 1333, then it makes sense to lower the RAM to 800 and tighten the timings and thereby lower the temps even though it's not 1:1 because the additional real world performance is negligible.
Additionally you could try 667 with even tighter timings at 1:1, but IMO the heat is no longer an issue at that point.
Many do not agree with me and really like the 1:1 ratio and tighter timings over all else.
halcyon
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- Dec 4, 2004
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Zorg and galta, thanks for the well written and, therefore, clear responses...you alleviated my confusion and hopefully the OP is assisted as well.
I like my Rampage Formula but its passively cooled NB at 1700+FSB gets no award for low temps under load. ...no need to push it without "real world" gain. ...its just that the OCZ HPC PC8500 Reapers take it so well, I'm always torn on what way to go.
To the OP, please forgive the intrusion.
I like my Rampage Formula but its passively cooled NB at 1700+FSB gets no award for low temps under load. ...no need to push it without "real world" gain. ...its just that the OCZ HPC PC8500 Reapers take it so well, I'm always torn on what way to go.
To the OP, please forgive the intrusion.
kpo6969
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http://www.anandtech.com/mb/showdoc.aspx?i=3208&p=9
What I use for normal use:
5:4
E8400 @ 3.6ghz 400FSB
PC2 8000 @ 1000mhz
http://i239.photobucket.com/albums/ff305/kpo6969/Temps701.jpg
1:1 is best for Nvidia boards though
What I use for normal use:
5:4
E8400 @ 3.6ghz 400FSB
PC2 8000 @ 1000mhz
http://i239.photobucket.com/albums/ff305/kpo6969/Temps701.jpg
1:1 is best for Nvidia boards though
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