2.2 GHz vs. 2.3 GHz (Mac)

General Questions
#1

I love my 15" PowerBook G4 (1.5 GHz PowerPC), and I really don’t need anything else. But I would like to get back into filmmaking, and it would be nice to have something more suitable; so I looked at the new MacBook Pro with the 17" glossy screen and the quad-core processor. Here are the processor options:

OK, that sounds pretty whiz-bang. It means nothing to me, other that it’s significantly faster than what I have now. But what is the upgrade? What does an 8 MB L3 cache and Turbo Boost speeds up to 3.4 GHz mean? Given that Macs have a reputation for being overpriced, and that ‘is it worth it’ is subjective, what makes the upgraded processor ‘worth’ an extra quarter-kilobuck?

#2

It’s not, unless you have money to burn. You wouldn’t notice the difference. Put the money into RAM (not from Apple).

#3

The upgraded processor is essentially identical (except for clock rate) to the slower one, except that it has a bigger L3 cache. How these changes translate to performance is not a simple question. With the best answer being “it depends”. In reality you would be unlikely to ever see a full 10% performance gain in all but the most contrived circumstances. The bandwidth to memory in unchanged, and for most compute intensive tasks this remains the most important bottleneck.

The reason these processors exist is three fold. One, Apple, like everyone else, need a product at the most premium price point, simply to sell to those that have the money, and feel the need to spend it. Two, there will genuinely be people that want the most bleeding edge performance. Where they need it is another matter. But the chips exist, Apple would be remiss not to offer them as an option. Three. The chips exist because the chips that come off the production line are tested for their operating range, some will work fine at higher clock rates. These are marketed at a premium price. Also, chips will often be defective, due to various glitches in the manufacturing process. In the past that simply meant it was useless. However nowadays L3 cache accounts for the lion’s share of die area, and the most likely place a defect arrives in in the L3 cache. So if you design the cache so that defective areas can be disabled, and the remaining good cache used, you can significantly increase your yield. Thus you may find that a 6MB chip is actually an 8MB chip with a defective cache bank disabled.

OK, but should you spend the money? Probably not. If you want to do movie work, more memory is most likely the best was to spend money. Apple have actually got more sensible with memory prices with this new release too. Still a premium, but not insane rip-off they were. The other, spendy, but spectacular way to get performance gains is a SSD. For movie work this could produce astounding gains. You might want to check in with some of the professional forums for opinions.

If you are doing movie or other visual work, I would be inclined to spec the anti-reflective screen option. Yes it looks a bit less snappy, but most visual professionals find the glossy screen a significant problem when critical work is done. That is the reason Apple still make the anti-reflective screen available, and after much protest, have reintroduced it on some models where it had gone.

The newer 17" machines are huge. I have one of the original PPC 17" machines, and it is only slightly bigger than the new 15".

#4

Cache is where the CPU stores the information it needs for processing. It is insanely fast memory. It takes about 3 or 4 clock cycles for the CPU to access it, which is like… 0.0000000013 seconds. That’s level 1 cache. Level 2 is slower. Level 3 is slower still. Decreasing the speed allows the size to increase though. Every time the CPU has to jump up a level of cache to find the information it needs, it slows way down. The worst happens when it leaves level 3 cache and hits system memory. More cache means this is less likely to happen. The faster the CPU, the more cache it needs to prevent this. Long and intense tasks like video encoding have the greatest demands on cache. Generally speaking though, 6 MB is considered the “plenty” point.

Turbo Boost is basically something Intel introduced to take advantage of what enthusiasts have been doing for years: overclocking. The CPU, when burdened with a heavy task, will increase its speed until it gets too hot to function. Not really though. Intel limits the increases to a safe point. Once it gets too hot, it backs off to its stock speed. So for short activities you’ll get a burst of speed. For something like video encoding, the turbo boost isn’t going to help a ton. Of course, if your heat dissipation is good enough, there’s no reason you can’t stay at the turbo speed permanently. That won’t happen with a laptop though.

As for the 2.3 GHz i7-2820QM vs. the 2.2 GHz i7-2720QM, the performance difference between 6 MB of L3 cache and 8 MB of L3 cache is going to be minor. The same is true of the minor clock speed improvement. It’s 3% at turbo speeds and 4% at stock. I’d be amazed if the two CPUs weren’t within single-digit-percentage of each other in terms of performance. I wouldn’t pay $250 for that. If you really care that much about performance, get a desktop. Any Sandy Bridge mobile CPU is going to destroy your old laptop, especially if you’re using something with a Intel QuickSync plugin for GPU-assisted rendering.

lol goddamnit.

#5

I have nothing to add other than to agree with other posters that for the type of work you are doing, additional RAM and fast access storage is going to be far more important than a marginally faster processor. (Even for computationally intensive tasks like solving large matrices of equations RAM and non-volatile storage, not cache or computational throughput, is the typical bottleneck.

I have to agree with Francis Vaughan as well that you really want the anti-gloss screen, especially if you’ll be using it to review dailies or other editing work on-site. The gloss screen works nice but reflects everything; Apple’s anti-gloss screen is about the best I’ve ever seen on a laptop and works pretty well even in direct sunlight. He is also correct that the MacBook Pro 15" machines are significantly wider than the PowerBook G4, and I assume the same for 17" machines. I have one of each of the 15" boxes, and the MacBook Pro is at least an inch wider, making it impossible to use the older sleeve or fit in some bags.

Stranger

#6

Interesting about the screens. The glossy screen was touted, IIRC, as being superior for editing. But now I see they’re charging extra for the screen similar to what I have on my PowerBook.

I have a Portabeace bag for my PowerBook. Love it. No way a 17" would fit in it though, so I’d have to get a new one.

I’m a shooter; not an editor. But it’s so hard getting a gang together, I’m thinking I should just shoot stuff on my own and see what I can do.

#7

I don’t know what it’s like in the video world, but most still photographers I know, myself included, swear by the matte screen. I hate the glossy screen. Don’t get me wrong–in the right viewing conditions, the contrast and vibrance on that screen really make images pop, but in most viewing conditions, I far prefer to have the matte screen.

#8

Pretty much what I think I heard. I couldn’t say myself, though.

#9

As someone who works outdoors day and night, I can’t agree more with all the people who suggested the matte screen upgrade. In direct sunlight with the glossy, you need to constantly adjust the monitor’s brightness settings depending on light conditions.

To the person who suggested buying ram from another company other than apple, which 4gb ram would you suggest? I am aware that in the 15’ MBP there are two slots for ram, made for up to 4gb each (8gb total), yet if the computer is ordered with 4gb stock (2gb + 2gb), wouldn’t it cost more than $200 to have to buy 2 4gb ram? Will the alternative ram company suggested have increasingly noticeable differences than apples.? Also, which SSD company would you suggest? I did some research and found numerous reviews praising intel’s x-25, due to the compatibility with the intel processor. Therefore, I tested the x-25 ssd in my black 05’ Macbook with a core-two duo and was very impressed with the speed upgrade. I retured it, but will purchase again when ssd prices drop.

A few months ago I purchased apple’s last updated release of the previous macbook pro 15’ when I thought my macbook had died. Yet, soon after I was able to fix it and returned the pro. Why I returned it: As much as I loved the uni-body, and light-up keys, a speed comparison showed barely noticeable differences. Even while running the exact applications on both, including vmware with windows 7 and xp going, along with several applications. The newest one does have a few cooler features, such as the new thunderbolt, yet no usb 3.0?! Either way, I have no devices that are compatible with either …yet. Bottom line is, if you think your going to gain invaluable time or processor speed by upgrading from a macbook or macbook pro made within the last 2-3 years, your not. If I absolutely needed a computer or for work purposes depending on high processing speed, yes.

#10

For a new MBP you can get two 4GB DDR3 for under $100. Apple is charging $200 for an upgrade from 4GB to 8GB. You could throw away the 4 GB that comes with it and still save $100. There’s no difference in function or performance.

There’s no compatibility difference between an Intel SSD and any other. There are differences in price and speed for a given capacity and there are frequent and significant changes, so do some research when you’re ready to buy.

#11

The OCZ Vertex 3 drops in a few weeks and it’s the dominate SSD if you have a 6Gb/sec SATA port. If you only have 3 Gb/sec, it’s still the best but only marginally better than the old stock 34 nm NAND SandForce-1200 controller-based drives like the Corsair Force series or OCZ Vertex 2. That should be accurate until the real 3rd Gen Intel SSD towards the end of this year.