Monday 5th January 2009
Tip 53 - MacOS [17] - What speed should I see.
People have been asking what scores they should expect from their computers well if you run the FULL Xbench test then you would hope to get more than 100 from any intel machine. I have tried to explain to people over and over that you cannot just look at the headline processor speed of a computer and know how fast it will be. The speed of a computer is a complex algorithm calculated from processor speed; hard drive speed; graphics chipset; graphics ram; ram amount; ram architecture; chipset; OS; OS updates; what software is running; settings on the computer; if a laptop then the battery settings (try max performance!); how long the computer has been on! etc etc etc
Now we can look any of my four Apple computers....
The one I am on at this moment
Macbook pro (17" (hi-res 1920x1200),200Gb 7200rpm Hitachi HTS722020K9500 HD, 2.5GHz core 2 duo, 4Gb Ram, Geoforce 8600M GT 512Mb)
Now I could have spent £100-200 (can't remember the actual extra at the time) on an upgrade from 2.5GHz to 2.6GHz, how would this have affected my computer?
REAL LIFE USE - None YES None. I doubt ANYONE here could tell the difference between a 2.5GHz and 2.6GHz Macbook pro
Xbench - Well the score will only benefit in SOME tests, 2.6 is 4% faster than 2.5 ie 2.6 divided by 2.5 equals 1.04! BUT there are VERY few tests that make full use of this speed as most of the time they will be waiting for the HD or GPU or something else.
ACTUAL difference in speed in reality 1-1.5%
What you actually need to improve is whatever is causing the bottlenecks. If you look at the spec of MY machine above I have upgraded the HD to a 7200rpm model - this cost about £20-30 over the cost of the 250Gb model but as this is not my main machine I do not need the extra space BUT the extra speed is more of a benefit.
I then increased the RAM myself as again this makes MORE of a difference than the processor in normal use.
Basically my 4Gb, 7200rpm machine will
easily be faster than a standard 2.6GHz machine and cost less !!
My
Mac Pro
QUAD 2.66GHz Xeon processors, 4x512Gb Ram+4x1Gb Ram (6Gb Total), Geoforce 1900GT, 3 x Seagate 500Gb HD + 1 x 250Gb HD
Now I'm not sure of the score of this machine as it is downstairs and off at the moment but how does this compare?
Well. Again 3 GHz is 12% faster than 2.66GHz but the ACTUAL speed increase is just 3%. 3.33GHz is 25% quicker than 2.66GHz but the actual increase is more like 6-7%
BUT if I am encoding a DVD without preview the increase in speed might be 8% for the 3GHz or 16% for the 3.33GHz because this is very processor intensive - The price however of the 3.33GHz was MORE THAN £1000 over my computer for 6-16% difference
DUAL against QUAD against EIGHT processors !!
Well in Tiger or Leopard you rarely see much of an increase when you go above 2 processors! UNTIL you run software that REALLY makes use of the extra processors such as video editing software or photoshop. ADDED: The only thing in Photoshop that I notice is significantly faster on my QUAD mac Pro against my DUAL macbook Pro is Liquify whilst it starts up!
Snow Leopard is reported to be far more capable of using the extra processors but this remains to be seen.
Other subsystems on the computer can make a BIG difference too.
RAM
Well this is the big one, let us imagine 3 Mac Pro computers with the same amount of ram in total.
a) 2 X 4Gb = 8Gb
b) 4 x 2Gb = 8Gb
c) 8 x 1Gb = 8Gb
Now RAM on the pro is QUAD channel ! The above computers ALL have the same amount of ram BUT computer (b) has all this in 4 pieces on 4 channels and is 10-15% quicker than computer (a) YES it makes more of a difference than going from a 2.66GHz to a 3.33GHz processor [in the right circs]. But what about computer (c) well this computer also has all channels running and so is quicker than (a) BUT there is a small decrease in speed due to the slight increase in lag so it is about 2-3% slower than (b) but still 12-13% quicker than (a).
What if you have 4 sticks of ram in a PRO? - Well if you have 2Gb in a pro and stick 2 more 2Gb in making 8 sticks then YES the speed decreases by 3% BUT the increase in ram from 2Gb to 4Gb makes MORE of a difference due to the computer not having to keep paging RAM to and from the HD!
[ADDED - If you have installed extra RAM in your pro then make sure it is in the right slots or you will loose about 15% as you will still be using 2 channels! - See my web site for details!]
So what am I saying?
Well make sure that any upgrades are balanced and worth the money! - 100MHz processor speed increase is virtually pointless (I feel that this is a bit of a rip off, any upgrade offered should be 200-300MHz really) but 2Gb-4Gb Ram upgrade is fantastic. Faster HDs make a big difference as does the graphics card but the amount of ram on the graphics card is
usually less of a help.
Is it worth upgrading?
Does your computer run too slow? - Ignore BOOT speed as it happens once and then goes away! Most Mac pros take 2-3 times as long as Macbook pros to boot but will leave them standing when the desktop appears! Speed on the desktop - Well go to Xbench and look at the speeds of different computers, you might have a 2.16GHz Macbook pro like ROOKIES and I might have a 2.5GHz well 2.5/2.16 = 1.15 ie 15% quicker (yes I know its not that simple when comparing different processor families and chipsets but this is a rough example
) now 15% is not much and when you consider that in reality the computer is not waiting for the processor that often my computer is more likely 7-8% quicker. This is a figure that is likely hard to notice!
I used to run CS2 on a 1.5Gb iBook 1.33GHz single core and created an A3 poster for work using Photoshop that's file contained 60+ photographs in different layers. It was usable (but slow) !!!!
Yes the modern machines are better but you have to reach 20% for the upgrade to be worth it (unless you have a lot more money than me
)
Why is my computer slow then?
Look at your settings? What processes start up when your computer does? etc etc
Things like little snitch or spotlight steal processor cycles and affect HD results, as do any other processes that run constantly! Check APPLE>>Accounts then unlock and select a user... Now select the "login items" tab and see what is starting when you turn on your computer!
Have you done all the updates?
Have you tried re-installing MacOS?