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what does santa rosa do?

furcalchick

furcalchick

macrumors 68020
Original poster
Dec 19, 2006
2,426
5
South Florida
if you noticed, the new pros have santa rosa in their chips while the new mb's don't and figure it's a way for apple to differentiate between the lines. i'm wondering about what santa rosa and exactly what it does to enhance the notebooks that have it, and will the macbooks will be hindered without it. i'm not even buying one, i'm just curious to know.
 
Santa Rosa brings several important benefits to the line-up, notably a boost in FSB from 667MHz to 800MHz, and slightly higher clocked processors available.

Santa Rosa
 
mags631 said:
For me, the biggest feature is the ability to address 4GB of memory.
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That too, but it's only slightly higher than the 3.2GB of the previous generation. I would of mentioned it, had I remembered, but I've just got home from a night on the town.
 
How much good does the faster FSB do when the RAM is the same speed as before? (Really asking, not being sarcastic or anything.)
 
Very valuable questions...

furcalchick said:
so for now, not too much in terms for a consumer/pro use. i would think that it was something major.
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I think it's just a step towards making computers faster and more power efficient. A lot of new hardware that comes out doesn't really revolutionize the way people use computers and such. It's really more of an evolutionary thing in my opinion.

xpovos said:
How much good does the faster FSB do when the RAM is the same speed as before? (Really asking, not being sarcastic or anything.)
Click to expand...

Good question...from my understanding, this would simply be an asynchronous system. That is, the RAM speed will still run at 677MHz, and the pathways between the...I think it's the northbridge chip and the CPU will run at 800MHz. So...again I could be totally wrong, but I believe that the northbridge interfaces both RAM, the video, and a few other things to the CPU. Since this resource is shared, it is slightly advantageous to increase the FSB speed.

Sorry if that's totally off. I haven't had to deal with computer hardware on that level for a long time!
 
samh004 said:
That too, but it's only slightly higher than the 3.2GB of the previous generation. I would of mentioned it, had I remembered, but I've just got home from a night on the town.
Click to expand...

But 4GB allows for dual channel use, while 3GB does not.
 
xpovos said:
How much good does the faster FSB do when the RAM is the same speed as before? (Really asking, not being sarcastic or anything.)
Click to expand...

Intel hasn't needed to have any connection between their bus speed and RAM speed for years now. Long before Apple switched to Intel.

aaronw1986 said:
But 4GB allows for dual channel use, while 3GB does not.
Click to expand...

Are you sure? I kind of thought you could still throw in 4GB, but the system would only see the first 3GB? At least I know some Dell systems with the same chipset let you do that, I thought.
 
A feature that I really like is that the chip can turn one of its cores off to boost the speed of a single-threaded application (the running core can boost its speed due to heat only being generated from one core).
 
furcalchick said:
so santa rosa isn't a major thing, but just pretty minor?
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Well, it's not earth shattering, but it is a good upgrade. Brings the mobile CPUs that much closer to their desktop counterparts, adds support for more RAM, etc.
 
furcalchick said:
so santa rosa isn't a major thing, but just pretty minor?
Click to expand...

Depends on your needs.

For some, being able to have a full 4GB instead of 3GB is a pretty big deal, for a lot it doesn't matter since they'll stay with the stock 2GB anyway.

The power savings and faster FSB are nice, too.
 
xpovos said:
How much good does the faster FSB do when the RAM is the same speed as before? (Really asking, not being sarcastic or anything.)
Click to expand...

hawaiian said:
Good question...from my understanding, this would simply be an asynchronous system. That is, the RAM speed will still run at 677MHz, and the pathways between the...I think it's the northbridge chip and the CPU will run at 800MHz. So...again I could be totally wrong, but I believe that the northbridge interfaces both RAM, the video, and a few other things to the CPU. Since this resource is shared, it is slightly advantageous to increase the FSB speed.

Sorry if that's totally off. I haven't had to deal with computer hardware on that level for a long time!
Click to expand...

It is asynchronous, but it's also dual channel. So you've got two 667MHz channels fitting into one 800MHz FSB, where previously you had two 667MHz channels fitting into one 667MHz FSB. All widths are 64bit.

Previously, dual channel mode didn't matter for this very reason -- the FSB was the same speed as a single memory channel. So, they just shipped with a single DIMM, since that made it easier to just add a second.

Now, dual channel can improve speed -- and now they ship with two DIMMs which enables dual channel mode. And, of course, it's also cheaper for Apple.

So yeah, there's a benefit. Maybe 5%... the large L2 caches will mask most of it anyway.

Oh, yeah... In Santa Rosa, the Northbridge talks to the RAM and the Southbridge. Video is on the PCI-E bus, which hangs off the Southbridge. However, some systems have PCI-E on the Northbridge, and some (mostly SLI) have it on both. Obviously, both North and South bridges talk to other parts too. Hope that elucidates :)
 
Episteme said:
...
Previously, dual channel mode didn't matter for this very reason -- the FSB was the same speed as a single memory channel. So, they just shipped with a single DIMM, since that made it easier to just add a second.

Now, dual channel can improve speed -- and now they ship with two DIMMs which enables dual channel mode. And, of course, it's also cheaper for Apple.
Click to expand...

It improved speed before. It's always improved speed running in dual channel mode, and Intel's FSB and RAM speeds haven't been connected in years.

Apple previously choose to ship it in a 1x1GB configuration probably just to be nice, to let us upgrade to 2GB easier.
 
http://www.macintouch.com/reviews/mbp15led/

"There has been some confusion about the MacBook Pro's 667-MHz memory speed vs. the 800-MHz frontside bus. Although 800-MHz memory is available in the marketplace, Santa Rosa doesn't support it. 667-MHz memory, we are told, is effectively 33% faster than Santa Rosa can use, so the lack of 800-MHz memory should not handicap this computer. "
 
Wolfpup said:
It improved speed before. It's always improved speed running in dual channel mode, and Intel's FSB and RAM speeds haven't been connected in years.

Apple previously choose to ship it in a 1x1GB configuration probably just to be nice, to let us upgrade to 2GB easier.
Click to expand...

Benchmark an MBP in single and dual channel mode. There's negligable difference. It's not about the speeds being connected, it's about bus widths -- you can't push 128bit@667MHz down a 64bit@667MHz pipe faster than you can push 64bit@667MHz...

You'll get the odd extra chunk of data due to access latencies, but most of the time the L2 will mask that anyway.

the MacBook does show an improvement, because the integrated video is in the Northbridge -- dual channel mode stops it being bottlenecked by the CPU accessing system RAM (and vice versa).
 
gkarris said:
Isn't this one of the ships Columbus sailed in? :D
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LOL.

It's also a town in Northern California, noted for Alfred Hitchcock being fond of it, and Charles Schultz living there. It's quite pretty. There's a Peanuts museum there too, which is pretty fun. They even have Peanuts cartoon strips in the bathrooms.
 
it sounds like expect for the ability to address 4 gb of ram, most of the changes are minimal to an average joe. i asked this because i was talking to someone and they thought core2duo and santa rosa were worlds apart, when really it's not.
 
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