• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

How much does cache really matter?

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

PanteraGSTK

Member
Joined
Jul 16, 2001
In my sig I have my trusty Core 2 Duo e6300 that has been a great processor. I've been able to run it at 3.5ghz until I got my evga 750i FTW board. I'm not sure if it is the board or the fact that Windows 7 isn't stable at that speed. I've tried everything. Back to the point. I'm going to get a quad for this board and would like to have a higher multiplier so I don't have to crank the fsb so high. I've narrowed it down to 4 processors.

First the q8400 and q9400. The only difference between them that I can tell is the L2 cache and possibly binning. The $20 difference would make me get the q9400 anyway but I wonder.

Second is the good old q6600. More cache than the first two, but in xeon form it is $20 more than the q9400 with 2mb more cache and a multi of 9 instead of 8.

Third is the q9550 with 4mb more cache than the q6600 bringing it to 12mb, and a 8.5 multi instead of 9.

Two more things. First is overclockability. I seem to remember the 45nm parts being able to oc more than the 65nm parts. That being said, everyone and their mom seems to run the q6600 at 3.6ghz with no problem. This is a fine speed for me. Second brings up the cache question. In gaming I've heard that is make little difference and that clockspeed is much more important. However, this cpu will find it's way into a server when I decide on a motherboard for my socket 1366 system. Isn't more cache supposed to be beneficial in a server?

Having said all of that I'd like to be more informed on the subject.

Thanks in advance.
 
I was checking this out a while ago and each step in cache for the same CPU type (45nm quads is what I was looking at) was equal to about 5% in overall performance or to put it another way equal to about 5% more clockspeed. Some programs it matters more, some less, but that general rule stuck across lots of website reviews.

Q6600 wasn't a 'guaranteed' 3.6 last I knew although you certainly see people's signatures with it...self-selected sample maybe? Back when they were the big thing 3.4 was a pretty reasonable 'guarantee' expectation and 3.6 and up was a bit less common depending upon your stability requirements. Also 45nm CPUs are at least 5% faster per clock than the Q6600.
 
I was checking this out a while ago and each step in cache for the same CPU type (45nm quads is what I was looking at) was equal to about 5% in overall performance or to put it another way equal to about 5% more clockspeed. Some programs it matters more, some less, but that general rule stuck across lots of website reviews.

Q6600 wasn't a 'guaranteed' 3.6 last I knew although you certainly see people's signatures with it...self-selected sample maybe? Back when they were the big thing 3.4 was a pretty reasonable 'guarantee' expectation and 3.6 and up was a bit less common depending upon your stability requirements. Also 45nm CPUs are at least 5% faster per clock than the Q6600.

True, the q6600's didn't all get to 3.6, but as you said there are enough people with them at that speed in their sigs. I think the 5% would matter enough to justify spending the extra $ on the 45nm parts. This will only be temporary so I'm not investing much.

Thanks.
 
L2 size is not something to worry about if gaming at a GPU bound resolution. even then the % increase drops off, it isnt always 5% for gaming. assuming your playing in a cpu bound res, from 512kb->1mb = 5.6%, 1mb-2mb = 4.6%, 2mb-4mb = 4.4%. these numbers might be a bit off after the 512kb-1mb, since it has been a while. i did read lots of reviews looking at L2 sizes, when they were comparing different cpus. L2 doesnt have much effect on anything else, expect FAH/Rosie, heavy number crunching. Things like 3D-rendering didnt show any improvement from a increase in L2, nor did A/V encoding apps. Those two only showed improvement from a increase in CPU speed.

*edit*
i found the thread that has this info
http://www.ocforums.com/showthread.php?t=546371
i never did at that time, put together that L2 size comparison.
 
Last edited:
And, you can't compare the 65nm to it's 45nm cache counterparts. The q8200 clocked @ 2.33ghz, with 4mB of L2 cache is faster than the Q6600 even if it has 8mB of l2 cache.

For 20 dollars extra, I would still take the q9400, but since your motherboard seems to have problem with high fsbs, you probably would be better with an higher multiplier quad, such as the q9505 (6mB of l2 cache) or a q9550.
 
And, you can't compare the 65nm to it's 45nm cache counterparts. The q8200 clocked @ 2.33ghz, with 4mB of L2 cache is faster than the Q6600 even if it has 8mB of l2 cache.

For 20 dollars extra, I would still take the q9400, but since your motherboard seems to have problem with high fsbs, you probably would be better with an higher multiplier quad, such as the q9505 (6mB of l2 cache) or a q9550.

I'm starting to agree with you. I think the 9505 is the best way to go. At the 8.5 multi and my rock stable 425mhz fsb that gives me a little over 3.6ghz. Assuming I can even get that high. I think that is what I will do.

Something random to add to this. I did a dice session a while back with my e63oo and since then it hasn't been the same. Might have something to do with the 1.8v I put through it. Since then I think my cpu may be to blame for the lower fsb. I've yet to put an aftermarket NB cooler on this board. My old 650i board suffered from high nb temps and my thermaright sli chipset cooler helped that quite a bit. All in all I don't actually know what the fsb limit of this board is. I've seen numerous reviews of it hitting over 450mhz fsb, but who knows.

Thanks for the help guys.
 
My old 650i board suffered from high nb temps and my thermaright sli chipset cooler helped that quite a bit. All in all I don't actually know what the fsb limit of this board is. I've seen numerous reviews of it hitting over 450mhz fsb, but who knows.

The only Intel's board with an nvidia chipset I ever used, was an MSI P6N SLI Platinum equipped with an i650 chipset. With the supplied northbridge fan I never could get the based frequency at more than 435mhz stable with the northbridge set @ 1.35volt.

As for the E6300, I only ever used the most recent Pentium 45nm version. 1 can do up to 510mhz and the other wont go higher than 475mhz based freq. and that is on a P5Q-E.

As for the q9505, providing you motherboard can do 425mhz stable, 3.6ghz should be a given.
 
The only Intel's board with an nvidia chipset I ever used, was an MSI P6N SLI Platinum equipped with an i650 chipset. With the supplied northbridge fan I never could get the based frequency at more than 435mhz stable with the northbridge set @ 1.35volt.

As for the E6300, I only ever used the most recent Pentium 45nm version. 1 can do up to 510mhz and the other wont go higher than 475mhz based freq. and that is on a P5Q-E.

As for the q9505, providing you motherboard can do 425mhz stable, 3.6ghz should be a given.

With my old gigabyte s3 965p chipset board I got the e6300 I'm currently using up to 540fsb. So I'm guessing it's not the chip, but who knows.

Check these out:

100% OC

Ghetto Dice session
 
First time I see dice being used that way. :)

I think that your fsb problem is more your motherboard than your cpu. Lower your multiplier to 6 and see if you can get an higher stable fsb.
 
You're my new hero.

Thanks. :D

First time I see dice being used that way. :)

I think that your fsb problem is more your motherboard than your cpu. Lower your multiplier to 6 and see if you can get an higher stable fsb.

I got the idea from looking at the stock intel cooler I used. It has a bowl built in so I wondered how well it would work. I got it down to -5c before putting 1.8v to it.

I think you are right. However, when I lower the multi to 6 I still top out at the same fsb. I'm thinking it has more to do with the crappy nvidia chipset overheating. I had that problem with my 650i board so I'm thinking it is the same with this one. I just don't want to rip off the NB cooler because it has a stupid heatpipe connected to the mosfet cooler.
 
I love my Q6600 but if i were going to buy a quad now i would go with the 45nm. Just because i have played with a few and i like them.

I think the 45s will clock higher than a Q6600(highest stable clock was at 3.8)
 
I love my Q6600 but if i were going to buy a quad now i would go with the 45nm. Just because i have played with a few and i like them.

I think the 45s will clock higher than a Q6600(highest stable clock was at 3.8)

I agree, but this will be a temporary cpu as I'm going to be getting an i7 system soon. When that happens this motherboard and cpu will be turned into a server. I'd rather not oc my server.

I think the q9505 is for me. 2.83ghz stock and a high enough multi to make me happy in the meantime. I just need to put a good hsf on the NB of the 750i board and I'm good to go.
 
9400 i thought has a high multiplier making it likely to hit a FSB wall faster?

how soon to your I7 system, why not grab a cheap e5 series that will clock high.
 
9400 i thought has a high multiplier making it likely to hit a FSB wall faster?

how soon to your I7 system, why not grab a cheap e5 series that will clock high.

It's going to be a few months until I get the i7 system so I want a cpu that will satisfy me until then. I plan to get one of the new 5970 or 5870 series ati cards for this system before investing in a new mobo, cpu and memory. That and the fact that when this computer changes from my gaming machine to the server when I get the i7 parts I would like to have a quad core for server duties. Basically, I'm getting a socket 775 quad anyway, so why not get one I can have some fun with before the whole new i7 system?

The q9400 has an 8x multiplier while the q9505 has an 8.5x multiplier. That extra clockspeed with the q9505 will hep with server duties as well as help me oc without the need for a high fsb.

EDIT: I forgot to add that the main thing keeping me from jumping into an i7 system now is the fact that I want to see how the boards with the Hydra 200 chips are going to work.
 
I seem to remember that quads are better for multi-card setups. Any truth to this?
 
9400 i thought has a high multiplier making it likely to hit a FSB wall faster?

fsb walls with 45nm quad cores LGA775 only happen on P35/X38/X48.. intel released something about this along time ago. P45 does not have FSB walls when ocing 45nm quad cores.
 
^^ good to know


yes, quads can help with multicards for sure, i7/i5 shines well in multi-card rigs i recall reading vs 775, at least i7 did when it came out.
 
^^ good to know


yes, quads can help with multicards for sure, i7/i5 shines well in multi-card rigs i recall reading vs 775, at least i7 did when it came out.

Well, then I guess the q9505 is what I'll be getting. I never had more than one card until I got my second 8800gt so I never thought about getting a quad. I wonder what the performance difference will be?
 
Back