1MB vs 2MB L2 Cache...

[Smoolean]

When looking at the Intel P4 530 and 630, aside from the EM64T, the big difference I noted were the 1MB vs 2MB L2 Cache. Common sense would tell me that a number twice as big as the other, must make a huge difference. An employee at a local computer store told me that the difference between 250K and 1MB on L2 cache is huge. Obviously I can do the math, but I've heard many people say that the 2MB on the 6XX series offers very little improvement compared to 1MB. I've heard some people say they didn't notice any difference.

So my question is, for someone on a rather limited budget who will be using his machine for mainly Photoshop and video editing (perhaps a little light gaming every once in a blue moon) would bumping up to the 630 be worth it?

Also, the difference between the two systems is $180, the 630 system comes with 1GB ram while the 530 only 512. $180 for a better processor and double the RAM sounds good to me, but then again I know virtually nothing about hardware. Would I be better of getting the 530 and finding my own RAM?

 

[PerfeK]

256K to 1MB is pretty big. The 1mb to 2mb is just about the same as bumping the clock speed up 100mhz in real world tests.

 

[fstime]

512K to 1MB is like bumping the cpu up 100mhz like the previous poster said,

 

[eXx08]

Because your a Photo shop user get 1 gig ram. You will see major performance gain in that. Not very big difference in 1mb cache and 2mb cache either. For what you need it for, you might notice a some what big improvment. If you can get 530 and 1 gig ram but if not get the 630 and 1 gig.

 

[Pabster]

Actually the increased cache on the Prescott-2 cores (6xx series) is there to compensate for the longer pipeline depth compared to Northwood (about 10 additional stages) and there is very little performance gain.

 

[PerfeK]

Originally posted by: Pabster
Actually the increased cache on the Prescott-2 cores (6xx series) is there to compensate for the longer pipeline depth compared to Northwood (about 10 additional stages) and there is very little performance gain.

^^This man speaks the truth.

edit: CPUs with larger L2 caches tend to do very well when using 64-bit registers.

 

[mwmorph]

Originally posted by: PerfeK

Originally posted by: Pabster
Actually the increased cache on the Prescott-2 cores (6xx series) is there to compensate for the longer pipeline depth compared to Northwood (about 10 additional stages) and there is very little performance gain.

^^This man speaks the truth.

edit: CPUs with larger L2 caches tend to do very well when using 64-bit registers.

arent the larger l2 chaches sometimes slower due to higher latencies?

 

[ProviaFan]

Originally posted by: PerfeK

Originally posted by: Pabster
Actually the increased cache on the Prescott-2 cores (6xx series) is there to compensate for the longer pipeline depth compared to Northwood (about 10 additional stages) and there is very little performance gain.

^^This man speaks the truth.

edit: CPUs with larger L2 caches tend to do very well when using 64-bit registers.

But unfortunately for the vast majority of Photoshop people, we have to use printers, and the printer drivers for XP64 just aren't there yet.

 

[Goi]

Originally posted by: mwmorph

Originally posted by: PerfeK

Originally posted by: Pabster
Actually the increased cache on the Prescott-2 cores (6xx series) is there to compensate for the longer pipeline depth compared to Northwood (about 10 additional stages) and there is very little performance gain.

^^This man speaks the truth.

edit: CPUs with larger L2 caches tend to do very well when using 64-bit registers.

arent the larger l2 chaches sometimes slower due to higher latencies?

Yup, I believe the Prescott's L2 caches actually have a higher load to use latency compared to Northwood.

 

[PerfeK]

Originally posted by: ProviaFan

Originally posted by: PerfeK

Originally posted by: Pabster
Actually the increased cache on the Prescott-2 cores (6xx series) is there to compensate for the longer pipeline depth compared to Northwood (about 10 additional stages) and there is very little performance gain.

^^This man speaks the truth.

edit: CPUs with larger L2 caches tend to do very well when using 64-bit registers.

But unfortunately for the vast majority of Photoshop people, we have to use printers, and the printer drivers for XP64 just aren't there yet.

Damn you, Epson!

 

[Smoolean]

So it sounds like the 630 isn't nearly as good as the average consumer would assume it is, but still, what would you pick if you had the choice between 530 and 630?

 

[Toolmantb]

http://www.officedepot.com/ddSKU.do?lev...=1000000447+10324+4294950850&An=browse

I've been looking at the Toshiba Satellite A75-S125. It's got Mobile Intel Pentium 4 processor 538 with Hyper-Threading Technology, operating at 3.2GHz
1MB L2 cache, 533MHz frontside bus.

Would it be safe to assume it would be noticeably faster than an Intel Pentium M processor 730 operating at 1.6GHz, 2MB L2 cache ?

 

[batmanuel]

Originally posted by: ProviaFan

Originally posted by: PerfeK

Originally posted by: Pabster
Actually the increased cache on the Prescott-2 cores (6xx series) is there to compensate for the longer pipeline depth compared to Northwood (about 10 additional stages) and there is very little performance gain.

^^This man speaks the truth.

edit: CPUs with larger L2 caches tend to do very well when using 64-bit registers.

But unfortunately for the vast majority of Photoshop people, we have to use printers, and the printer drivers for XP64 just aren't there yet.

Can't set up your system to dual boot? Do all of the heavy PS lifting in XP64, make a flattened version of the image to proof that won't take forever to load, and then reboot into XP32 when you are making your prints. If you are working on a big enough image for you to see a significant increase in productivity by working in 64-bit mode, it might be worth the trouble. It usually takes so long to print large inkjet images that I usually just run a big batch and take a break while it is printing, anyway, so rebooting wouldn't slow me down that much.

 

[Concillian]

Cache sizes are not as important as people make them out to be. The difference between 256k and 1MB on some core designs and apps is huge, and on other core designs and apps is virtually non-existant.

As has been said, the core designs of the two processors are sufficiently different that the real-world performance difference is not much at all.

To toolman, the Pentium M and P4 designs couldn't be much more different. the P4 will probably be faster most of the time, but not as much as you'd think by the p4 being twice as fast. The Pentium M does much more work per clock cycle than the P4, but probably not quite twice as much.
You can see from Anand's benchmarks, that a 725 is not terribly different from a 640 in photoshop 7.01, though he doesn't test in newer versions:
http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2382&p=5
So a 730 and 538 should be pretty close, probably not in the realm where one would be 'noticeably faster' than another in Photoshop. Other applications show larger differences. In a laptop type computer, I'd probably go with the Pentium-M because power consumption of the M will be much better, as it is significantly more power efficient than the P4.

 

[Bona Fide]

For the most part, a doubled L2 cache equates to a 200MHz bump in speed.

A64 3500+ @ 2.4GHz = A64 3700+ @ 2.2GHz

P4 540 @ 3.4GHz = P4 640 @ 3.2GHz

 

[ChoppedBroccoli]

Originally posted by: Goi

Originally posted by: mwmorph

Originally posted by: PerfeK

Originally posted by: Pabster
Actually the increased cache on the Prescott-2 cores (6xx series) is there to compensate for the longer pipeline depth compared to Northwood (about 10 additional stages) and there is very little performance gain.

^^This man speaks the truth.

edit: CPUs with larger L2 caches tend to do very well when using 64-bit registers.

arent the larger l2 chaches sometimes slower due to higher latencies?

Yup, I believe the Prescott's L2 caches actually have a higher load to use latency compared to Northwood.

Right on the money. The bigger the cache, the more time goes into addressing the cache. How to address it, whats the replacement policy, and other interesting schemes all contribute to latency (all this stuff makes sense to me know that I just took my computer architecture courses in college ).

So while I think 'cache was king' (ie really important) some years ago (when we were dealing with cache sizes of 64, 128, and 256K), now its not always the determining factor (at least among the higher performing chips). The AMD chips had 1MB caches but then switched back to 512K once they improved the memory interface.


I'd say the extra ram should definitely be your priority.

 

[Goi]

Right out of Hennessy and Patterson eh?

 

[AmberClad]

Originally posted by: Goi
Right out of Hennessy and Patterson eh?

Wow, that textbook must be even more ubiquitous than I imagined...

 

[ChoppedBroccoli]

Originally posted by: AmberClad

Originally posted by: Goi
Right out of Hennessy and Patterson eh?

Wow, that textbook must be even more ubiquitous than I imagined...

Lol...yes!

HAHA, must be standard issue for any CS/CE student.

 

[Cerb]

Originally posted by: Bona Fide
For the most part, a doubled L2 cache equates to a 200MHz bump in speed.

A64 3500+ @ 2.4GHz = A64 3700+ @ 2.2GHz

P4 540 @ 3.4GHz = P4 640 @ 3.2GHz

...except that that 3500+ 2.4GHz will beat the 3700+ 2.2GHz in all but handful of tasks.

 

[stevty2889]

The only real advantage the teh 6xx series has is that it runs a bit cooler. The larger cache doesn't seem to help much at all, I believe it has even higher latency than the 5xx series. Photoshop will definatly take advanatage of 1gb of ram, and video editing can use more than 512mb pretty easily as well.

 

[stevty2889]

Originally posted by: Toolmantb
http://www.officedepot.com/ddSKU.do?lev...=1000000447+10324+4294950850&An=browse

I've been looking at the Toshiba Satellite A75-S125. It's got Mobile Intel Pentium 4 processor 538 with Hyper-Threading Technology, operating at 3.2GHz
1MB L2 cache, 533MHz frontside bus.

Would it be safe to assume it would be noticeably faster than an Intel Pentium M processor 730 operating at 1.6GHz, 2MB L2 cache ?

No, not really. The pentium-M is a much more effeciant design, my pentium-m 1.6@2.4ghz, is faster than my P4 @3.82ghz in a lot of things, especialy gaming. Mobile pentium 4's will suck the battery dry pretty quick too.