3MB L2 vs 6MB L2 Real Performance Difference?

When configuring a laptop the CPU is a very important part, even more if it is a workstation.

This question popped up right away when I configuring a W500.
With the P8800 at 2.66 if not mistaken and 3MB L2 Cache, how does it compare to a similar T9550 at 2.66 with same FSB but double the L2 Cache?

Let us set aside the TDP, consumption, heat, and all of that. I am merely interested in raw power. How does the 6MB L2 Cache really outperform the an exactly-the-same-speed-and-FSB CPU?

Other clear example would be the P8700 at 2.53 vs the P9500 at 2.53, the both use the same 25W, same FSB, same clock speed, same heat/energy/etc. How does the P9500 really outperform in practical life the P8700? For example on the same W500, using it for SolidWorks, is there really an advantage with the bigger L2?

Thanks for your help! This might end up being really helpful for all high-end users out there.

 

Depends what you are using it for. Majority of the time, you won't see any difference. Only under full load, doing certain tasks, might you see a small difference - about 5-10% at most. Unless you are timing a task, I doubt in real life would you even notice that though.

 

This gives a good of the performance increase of 6MB chache AND 0.1 Ghz clock:

"The performance increase due to the clock speed and cache size increase varies from 0% all the way up to 11.7%, with a maximum of around 4% of that being due to the clock speed increase alone - the added L2 cache does have a benefit. "
http://www.anandtech.com/mac/showdoc.aspx?i=3246&p=12

 

Then why do the upgrade form a P8x00 to a P9x00 is so pricey?
For example the P8800 is a $50 upgrade on the W500 while the P9500 is a %250 upgrade on the same machine...

Is it so hard to make such a difference?

 

not sure why. Intel is known for charging crazy prices. Remember the T9300 and the T9500? ~$300 for 200Mhz difference.

 

Most people have no clue about CPUs and what they need. They'll just buy the highest specs. I like to call them specbuyers.

 

funny, I know exactly what you mean

 

Every time I see that chart I do a double-take. Minimal to zero performance benefit working with images and video, but 10% or greater performance doing common tasks in MS Office? I'm sure the figures are right. And anyway, I'm not nearly smart enough to question the results - they just seem surprising for some reason.

The upcharge for the 6MB CPU with equivalent clock speed isn't always huge Depends on the manufacturer and on timing. Hard to resist a little spec-shopping when the price difference is minor

 

So the 6MB is NOT worth the 200?? (I know it sounds rather childish and foolish to ask this)

 

Guess it depends on how often you'll be comparing documents in Word.

I have to think you can buy much greater performance by spending the $200 on one of those new Intel SSDs, though.

 

If your job is comparing documents with Microsoft Word and you're paid by performance and you earn $100 an hour with 3Mb cache, you'd earn $108 with 6MB cache. The investment would pay for itself in 25 hours.

Other than that, no it's not worth it.

 

Unless you want a power point presentation 2 seconds sooner, than no.

 

HAHAHA I just re-read my question...what was I thinking?

Ouch! That hurts! (naah just kidding) I do know my way around CPUs. But I just wonder why the charge so much if it wont really offer any performance increase. Just to take advantage of newbies? That is mean!

 

Yeah, I don't think it's worth the price premium at all for double the cache - you'd be better off spending on an SSD, as chris-m mentioned.

 

The 6MB CPUs may be popular in professional environments where every second counts. Science or stocks for example.

They don't make sense for consumers.

 

Well, I need the laptop for SolidWorks and CATIA for my university studies.
On this CAD-based softwares, does the 6MB have any noticeable effect?

 

I recently replaced my T9500 (2.6GHz, 6MB L2) with a P8600 (2.4GHz, 3MB L2). Not exactly the same clocks, but fairly close. So far, I haven't noticed any difference at all, except for maybe an extra half hour of battery thanks to the P8600's lower TDP. As far as I can tell, there is absolutely no difference in boot time, opening up or saving documents, or even gaming.

 

I think cache primarily helps calculations. That's why compare documents and zip/unzip benefits most.

Does CAD rely on calculations?

But then again, even if it does, you're only looking at 5 to 8% increase.

 

Then those 200 are NOT worth it...such a shame manufacturers do this, but well.

I think this thread has fulfilled its purpose, unless someone else has anything to add.

Thanks everyone! You have been very helpful!

 

Cache is most important in games. If you are held back by the graphics, doubling the cache from 3MB to 6MB could net you 20% or more of an increase in framerates.

 

Proof please? Mind you, I've used several different processors, ranging from 1MB to 6MB, and have never noticed a difference in gaming.

 

Wait, what? I thought games were GPU-dependant...what does the L2 Cache from the CPU has anything to do with the game?

 

Most games are GPU dependent, hence why you won't notice much of a difference upgrading your CPU. The only games that would notice a difference are physics/calculation intensive ones like Supreme Commander and GTA IV (there are a few more but relatively little list compared to the amount of GPU limited games).

 

But even those games won't benefit 20% from 6MB cache.

 

so 6MB cache is basically useless...

 

To most consumers and gamers, yes, it is useless. To people who require a fast CPU for work, no.

 

work as in crunching numbers and zip/unzip, comparing docs, and stuff yes.
But it would seem that even when 3D modeling it wont add much..

 

Sorry, I am huge on desktop hardware and am new to the mobile thing. You need to have the graphics power to take advantage of increased cpu processor capability. The effect of the CPU on framerates on the desktop is huge when you are running higher end cards. You on the other hand are using pretty much bottom end discrete graphics from a desktop point of view, so it is no wonder your cpu is already more than enough for the gpu. And sorry, I was thinking about from 2MB to 6MB when I said 20 or more %. This is also only for a dual core. I guess its really a moot point when talking about laptops as my old "reserve" video card is probably a lot better than anything you can find on a laptop.

 

L2 cache does have an effect on games, though realistically, it is a small effect.

 

My desktop has two overclocked 8800GT's in SLI, and I've used several processors in that as well. The graphics are definitely not bottlenecking anything.

 

I would say just pay for something which is useless in our daily use.

 

The difference may be higher in tasks like video encoding/decoding (e.g. converting an avi/divx file to DVD format before burning).

 

I use AutoCAD, Max, photoshop and other stuff and the differece in price is not worth the extra 3-4% (on average) in speed/time .

 

Cache does actually have an effect on games, of course not the 20% mentioned above but it is still there. If we compare intel desktop processors where they sell harvested CPUs with the same architecture + clockspeed but less cache, such as the Q8400/Q9400

http://anandtech.com/bench/default.aspx?p=89&p2=76

you do see some improvements in gaming and many things actually (This is 4MB vs 6MB as opposed to 3MB vs 6MB so I guess you can argue the difference would be even greater on a laptop CPU). But when you look benchmarks such as blender and 3dsmax the differences really are not that great and hundreds of dollars simply for extra cache is definitley not worth it. Their cinebench scores look a bit whacky on multithreaded to me but regardless this is overall a good comparison between two CPUs with same clockspeed+architecture but different cache.

 

Omg, I swear when I went from a dual core 2MB l2 cache to the 6MB l2 cache quad core with two cores disabled at the same speeds, at the 1600x1200 resolution I play at, and my volt modded and water cooled HD 4890, there was a huge improvement in FPS.

 

Thanks for that Anandtech link. Here is what I'm talking about:
http://anandtech.com/bench/default.aspx?p=58&p2=98
http://anandtech.com/bench/default.aspx?p=57&p2=94

 

Let's think about this logically here. Cache speeds up memory access to a small amount of data by keeping it "closer" to the CPU. Software programmers, especially game programmers, are all about squeezing every ounce of performance out of the middle of the range of target hardware they are developing for. If most machines on the market have 1-2M of cache, they are going to work hard to make the game run with 1-2M max of frequently accessed data, and to minimize the noticible impact of cache misses as much as possible by trying to make them happen when things are hung up on the GPU or something else. As a result, as long as you have as much or more cache than what the devs were targeting, you won't see much difference when upgrading to a higher cache CPU. However, what is mid range is always going up. So that means in the future, you will probably see more and more impact from more cache as devs rachet up target specs.

 

LX cache memory is very expensive when compared to RAM and other mediums.

It's on die and VERY fast. MUCH faster than any RAM. The only reason we see such small amounts is because of the cost.

 

I somewhat disagree with you Matt. Small amounts of Lx Cache is more due to it being integrated in the cores, therefore it cannot be that large. And since they are bits stored there, just to help the CPU process whats on the RAM faster, it is not required that much.

But yeah, for stressing the CPU, the more, the better...lol

 

If a person is doing simple tasks such as these, why are they even considering a CPU upgrade? IMHO those tests are irrelevant to the type of tasks that the "power users" are considering.

I have a notebook with a P8600 (2.4GHz 3MB L2), that I just upgraded to a ES T9400 (2.53GHz 6MB L2). I can already tell a big performance gain, most noticeably in L4D. (I've only used this cpu for ~1 day so far)

My CPU is always getting it's balls stomped:
When I work I use AutoCAD, MATLAB, Inventor, etc.
When I play I use Left4Dead, Counter-Strike Source, HL2, etc.
And when I'm not playing games, and when I am plugged into a power outlet (90% time) I am running einstien@home on both CPU cores, and GPUGRID on the GPU.

I hate this whole "average home consumer" vs "workstation computer" ordeal. Because from my experience most of the people that I know put more stress on their computers when they are at home being "average home consumers" From playing games, watching 1080p movies, running itunes visualizations, etc etc.

The only time that I can think of a workstation seeing much more use (aside from video editing), is when the worker is playing games, watching 1080p movies, running itunes...while also running the work related apps in the background for when the boss comes around

 

I agree. Anandtech made a very strange choice there.

 

So what I understand is that a workstation wont see any upgrade but a home user will? WHAT?

 

how about swapping from 2.53 ghz p8700 to 2.00ghz q9000?

 

Depends on the tasks your are performing. If you work on a multithreaded program such as MATLAB or AutoCAD, then you will. Else you will find it slower.

 

You sure it's only the cache? If you went from, let's say, a C2D E4500 to a E8500, there's a big difference and it's not only cache....