memory speed benefits

[procreate]

what are the benefits of running higher frequencies with memory. say between running 667 vs 800. what type of applications will benefit from higher speeds, which would be unaffected?

[uOpt]

Basically - none. The advantage for non-compression, non-encryption applications is very limited and generally between 0-3%.

http://forum.useless-microoptimizations.com/forum/crabench-memory.html

[flclisgreat]

yup. the only real difference will be benchmarks.

[Gas Pipe Jimmy]

Thanks for melting my brain uOpt. :p

What you are saying is that we could save a bunch of money by just using 667 memory instead of the 800 or higher stuff?

3% is a pretty small benefit in my book.

[flclisgreat]

Thanks for melting my brain uOpt. :p

What you are saying is that we could save a bunch of money by just using 667 memory instead of the 800 or higher stuff?

3% is a pretty small benefit in my book.



yes. people just buy higher speed ram because they don't know, or they overclock.

[PaulTa]

yes. people just buy higher speed ram because they don't know, or they overclock.

I dunno man, right now those firestix on newegg are going for 190 bones (2 gigs). That's 190 bones for 1000mhz mem. at 4-4-4-12 timings for anyone who can change a couple of numbers in a bios. :D

[flclisgreat]

I dunno man, right now those firestix on newegg are going for 190 bones (2 gigs). That's 190 bones for 1000mhz mem. at 4-4-4-12 timings for anyone who can change a couple of numbers in a bios. :D

not a bad price. i paid $260 for my g skill HZ(2gb), for 4-4-3-5 @ 500mhz

[PaulTa]

not a bad price. i paid $260 for my g skill HZ(2gb), for 4-4-3-5 @ 500mhz

Not bad. Anything under 4-4-4-12/10 is pretty much bragging rights or for benchmarking. Being the OCing noob I am, I'll stay with 4-4-4-10 until I can train my skillz higher.:p

I've read about guys pushing the firestix that I was talking about to around 1150/1200 with 5-5-5 timings on overclock.net. Those guys over there could teach me a thing or two about OCing me thinks.

[flclisgreat]

Not bad. Anything under 4-4-4-12/10 is pretty much bragging rights or for benchmarking. Being the OCing noob I am, I'll stay with 4-4-4-10 until I can train my skillz higher.:p

I've read about guys pushing the firestix that I was talking about to around 1150/1200 with 5-5-5 timings on overclock.net. Those guys over there could teach me a thing or two about OCing me thinks.

the highest I've had this HZ is 560mhz cas 5. but that is cpu/mobo limited on my AMD system

[PaulTa]

the highest I've had this HZ is 560mhz cas 5. but that is cpu/mobo limited on my AMD system

That's still very impressive, but I have heard of people taking that RAM to about 1200/1250 on acceptable timings with stability. When you get a new mobo/cpu, you can tax those things and update the results for me! :D

[flclisgreat]

That's still very impressive, but I have heard of people taking that RAM to about 1200/1250 on acceptable timings with stability. When you get a new mobo/cpu, you can tax those things and update the results for me! :D

c2d when the prices drop, so if i remember i'll update you

[Hutch]

Higher speed ram is basically only beneficial to us overclockers, especially with core 2 systems. The p965 chipset doesn't have ram ratios below 1:1, so when we're pushing FSBs high, the lowest speed we can run the ram is the same speed the FSB is running. 450mhz FSB = 900mhz ram, 500mhz FSB = 1000mhz ram. For non-overclockers, you'll never notice the difference.

[procreate]

say its IN a C2D system, 975 chipset... applications push the CPU to 90% frequently and use a heafty about of RAM constantly.

[PaulTa]

Is the C2D overclocked?

If yes, then you want the FSB to match the RAM speed with a 1:1 ratio for best performance. If that means sacrificing timings, I believe it's better that way (someone make a double check on this for me? I'm kinda new to this stuff).

C2D systems are more picky about mhz speed than lower timings, as where AMD is a bit tilted in the other direction.

[uOpt]

Thanks for melting my brain uOpt. :p

What you are saying is that we could save a bunch of money by just using 667 memory instead of the 800 or higher stuff?

3% is a pretty small benefit in my book.

Absolutely.

My benchmarks are not the only ones clearly showing this.

Fast RAM is a bad investment cost/speedup wise. Money is clearly better invested in higher clockspeed CPU, better cooling, better graphics if you are a gamer, better harddrive for almost everybody (although it's not popular because it doesn't improve framerates).

Some people like good RAM because they just like to have good stuff, or the best. That's fine but let's be honest here - with the recent increase in RAM prices that's a pretty expensive hobby.

Some people also like to buy expensive RAM because they think it's more reliable, but to be honest my experience doesn't support that theory. To get more reliable RAM you have to buy RAM that the vendor markets are more reliable, e.g. through more testing, not as faster RAM. All the overclockign vendors like OCZ, G.Skill and Mushkin have, sorry, pretty lousy QA on their normal retail RAM. You need to buy their "professional" stuff.

[uOpt]

Higher speed ram is basically only beneficial to us overclockers, especially with core 2 systems. The p965 chipset doesn't have ram ratios below 1:1, so when we're pushing FSBs high, the lowest speed we can run the ram is the same speed the FSB is running. 450mhz FSB = 900mhz ram, 500mhz FSB = 1000mhz ram. For non-overclockers, you'll never notice the difference.

Wait, the p965 doesn't have 4:5 and 5:4, only the x975 does? :eek:

[PaulTa]

Absolutely.

My benchmarks are not the only ones clearly showing this.

Fast RAM is a bad investment cost/speedup wise. Money is clearly better invested in higher clockspeed CPU, better cooling, better graphics if you are a gamer, better harddrive for almost everybody (although it's not popular because it doesn't improve framerates).

Some people like good RAM because they just like to have good stuff, or the best. That's fine but let's be honest here - with the recent increase in RAM prices that's a pretty expensive hobby.

Some people also like to buy expensive RAM because they think it's more reliable, but to be honest my experience doesn't support that theory. To get more reliable RAM you have to buy RAM that the vendor markets are more reliable, e.g. through more testing, not as faster RAM. All the overclockign vendors like OCZ, G.Skill and Mushkin have, sorry, pretty lousy QA on their normal retail RAM. You need to buy their "professional" stuff.


I agree with uOpt, but lately you can find really high speed RAM for about the cost of ValueRAM. Check out buffalo Firestix PC2-6400 (2x1 gig). It's going for about 170-190, and has great OCing potential. You can get this stuff to about 350$ RAM speeds if you know what you're doing.

[procreate]

my 975 runs a 2:3 ratio stock.

i was curious because i run APPs like After Effects which uses RAM to preview the composites. i can only get so far before i run out.... and if it helps rendering as well.

so until the 965xbx2 supports 1066 [8500], there isnt much of a performance increase? i heard 3-8% tops between 667-800 around various places.

i also havent heard good things about those buffalo sticks really.

[procreate]

while i am asking the speed, how much does latency affect applications?

[uOpt]

while i am asking the speed, how much does latency affect applications?

The benchmarks I posted have both.

In general the effect is about equal. Clearly, the middle ground with good timings and moderately high memory clockrates works best for real-world apps. BH-5 at 2-2-2-5 250 MHz was clearly faster than TCCD 3-4-4-8 at even 320 MHz (see the benchmarks).

In DDR2 you should aim at the maximum clockspeed at 4-4-4-x instead of driving the clockspeed higher at 5-5-5 or worse. 3-3-3-x at it's maximum is probably even better but that might have too severe restrictions on memory clocks.

Of course the problem is, as mentioned, that availability of memory dividers in Core2 put a quick stop to optimizing games like that and you might not have the choice to run lower memory clock with better timings. That's why the extreme editions of the CPUs make sense.

On the bright side, none of it really matters as long as you are not too slow. For example, in the AMD64 going from 200 to 166 MHz gave you a noticeable real-world performance loss, but going up the same factor from 200 to 240 gave you much less of a benefitt. There is a reason why CPU makers pick their defaults, they are not stupid.

Or to make it short: if you can do DDR2-666 with 4-4-4 I bet everything better is in the noise (unless you do useless benchmarks like SuperPi or compression).

[Hutch]

The p965 chipset allows 1:1, 4:5, 2:3, 3:5, 1:2 but doesn't allow 5:4 ect.

I'll post some benchmarks if you want showing differencies between timings, 400mhz cas 3 vs 400mhz cas 5 is about a 1-3% improvement...

DDR2 prices have completely tanked... You can get micron D9GMH for under $250 now, D9GKX (the best of the best) for under $300...

[Gas Pipe Jimmy]

I have a very specific question about memory on an Intel 975BX2 (Bad Axe2) motherboard.

My question is: how low I can go on speed rating (and expense) for memory if I intend to overclock a 2.4GHz to something North of 3GHz. Maybe 3.2GHz, but I will go as high as I can get.

Can I get away with 667 or 800 or am I stuck with the higher than 800 speeds?

I used to know all of this stuff but I have been out of overclocking for about 7 years now and what I haven't forgot has all since changed. :confused:

[flclisgreat]

I have a very specific question about memory on an Intel 975BX2 (Bad Axe2) motherboard.

My question is: how low I can go on speed rating (and expense) for memory if I intend to overclock a 2.4GHz to something North of 3GHz. Maybe 3.2GHz, but I will go as high as I can get.

Can I get away with 667 or 800 or am I stuck with the higher than 800 speeds?

I used to know all of this stuff but I have been out of overclocking for about 7 years now and what I haven't forgot has all since changed. :confused:

guessing e6600?

well with ram @ 1:1 and FSB to be around 350 for 3150mhz. its simple math here really. multiplier of 9xFSB=mhz. you want 3.2 so thats about 356FSb so you will need ram that will do that, or better.

[Gas Pipe Jimmy]

Yes, I'll be starting with a 6600
356x2 = PC6400 DDR2
Kinda sorta? :confused:

[flclisgreat]

Yes, I'll be starting with a 6600
356x2 = PC6400 DDR2
Kinda sorta? :confused:



pc6400 is ddr 800 which is 400 effective mhz. so with a ok set of ddr 667(667 divided by 2 is 333mhz, and you want 356 1:1 FSB. so you should be ok.) but you may not. this is why people buy nice sets of pc6400, to run it 1:1 and get a nice oc on there cpu to 400 FSB and run the ram stock.

[Gas Pipe Jimmy]

Thank you flclisgreat, that's exactly the info I needed!
:)

So I could probably get bye with 667 but if I want to be sure, then 800 it is.
Great!

[PaulTa]

Thank you flclisgreat, that's exactly the info I needed!
:)

So I could probably get bye with 667 but if I want to be sure, then 800 it is.
Great!

Well the way RAM prices have tanked recently, you could get a set of 800mhz memory for a few dollars more than most 667mhz memory.

As usual, I would suggest Buffalo Firestix PC2-6400. On newegg, they're about 190 bucks, and they have the same chips inside that are on a lot of 300$ kits of memory. It's really a solid buy that will leave you with plenty of headroom for the future.

http://www.newegg.com/Product/Product.asp?Item=N82E16820150054

I wouldn't suggest anything from Corsair right now if you decide to go with something else and you want to overclock. They really are government sanctioned pirates! :p

[Gas Pipe Jimmy]

Thanks for the suggestion PaulTa.
But I have to admit that I'm reluctant to buy any memory when the manufacturer specifies anything more than the DDR2 standard 1.8v.

I suspect that the memory sticks that require 1.9v-2.2v are nothing more that 667 sticks that are already "overclocked" by the manufacturer, specified with higher latencies, and then labeled as a "performance" part and priced accordingly.

If I'm wrong on this assumption of mine, please feel free to correct me, but I think this data sheet from Kingston confirms my suspicions.
http://www.valueram.com/datasheets/KHX6400D2LL_1G.pdf

[procreate]

I wouldn't suggest anything from Corsair right now if you decide to go with something else and you want to overclock. They really are government sanctioned pirates! :p

i dont know if that is exactly a fair statement... i havent heard nearly as good of things from buffalo as i have heard about corsair. the only thing i have seen people upset about is the 6400C4D which they use Promos when people thought they were buying D9 IC's... and i saw some guy who OC'd the 6400C4Ds quite heavily even with the later version [which i now understand could be elpida or infineons depending on the rev]

that said, im not really concerned with OCing or how it relates to gaming... sadly almost ALL information on the net in about gaming with high performance computing. i can understand with all the real time rendering that must take place, but i wish at times there were places [or people] who knew about other applications such as audio and video dealt with parts and their benefits.


from what im gathering however, it seems if i did overclock i would see more benefit from getting this 6600 up to the 3ghz range than running 667>800 memory, although the 800 might be easier to get the CPU up in speed? is this right?