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Will This Mem Work & Max Mem? (4,1)

S

Syndacate

macrumors regular
Original poster
Mar 16, 2008
127
0
Hey,

I'm looking to buy my g/f some memory for Christmas.

I'm 90% sure she has a MBP 4,1 (either a 4,1 or a 4,2, I don't have the computer in front of me).

I was looking at buying this memory:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145193

This will work, correct?

Also, would doing 6GB with this combo be feasible? :
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220495
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220229

Reason I ask is I remember somebody saying at one point that 4GB was the 'cap' - but it used 6GB fine, and 8GB made it laggy. Forgot where I heard that, though, might just be a myth. Would 6GB cause speed problems due to it being dual channel with a 4 & 2?

She keeps every ****ing application possible open at the same time, hers only has 2GB, and it's nowhere near enough, so it's paging like a bitch and making the computer slow as all hell once she's used it for about a day.

TIA!
 
Syndacate said:
Hey,

I'm looking to buy my g/f some memory for Christmas.

I'm 90% sure she has a MBP 4,1 (either a 4,1 or a 4,2, I don't have the computer in front of me).

I was looking at buying this memory:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145193

This will work, correct?

Also, would doing 6GB with this combo be feasible? :
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220495
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220229

Reason I ask is I remember somebody saying at one point that 4GB was the 'cap' - but it used 6GB fine, and 8GB made it laggy. Forgot where I heard that, though, might just be a myth. Would 6GB cause speed problems due to it being dual channel with a 4 & 2?

She keeps every ****ing application possible open at the same time, hers only has 2GB, and it's nowhere near enough, so it's paging like a bitch and making the computer slow as all hell once she's used it for about a day.

TIA!
Click to expand...

The 4,1 will take a max of 6GB, your information is correct.

I believe macsales.com has a 6Gb kit you can buy all at once.
 
snaky69 said:
The 4,1 will take a max of 6GB, your information is correct.

I believe macsales.com has a 6Gb kit you can buy all at once.
Click to expand...

Thanks.

Yeah, I found this there.

Only problem is it's 50% more expensive than matched Patriot memory 4 & 2 bought separately, and I've never heard of OWC RAM.

In any event, will she run into speed issues because the RAM isn't matched if you put a 4x1 and a 2x1 in there (DDR2 is dual channel)?
 
Syndacate said:
Thanks.

Yeah, I found this there.

Only problem is it's 50% more expensive than matched Patriot memory 4 & 2 bought separately, and I've never heard of OWC RAM.

In any event, will she run into speed issues because the RAM isn't matched if you put a 4x1 and a 2x1 in there (DDR2 is dual channel)?
Click to expand...

No speed problems whatsoever will arise, I don't see why there would be any. OWC is as reputable a brand as any as far as RAM goes. You lose the dual channel but you have 2gb's more before you start using virtual memory, so the point(to me) is moot.

Just match the specs of said RAM from whatever brand you prefer on another site.
 
snaky69 said:
No speed problems whatsoever will arise, I don't see why there would be any. OWC is as reputable a brand as any as far as RAM goes. You lose the dual channel but you have 2gb's more before you start using virtual memory, so the point(to me) is moot.

Just match the specs of said RAM from whatever brand you prefer on another site.
Click to expand...

Yeah, I guess it's like going from a 250GB drive at 5400 RPM to a 100GB drive at 7200 RPM, or a 500GB drive at 5400 RPM.

Losing the dual channels means you have a higher access latency. On the flipside, as slow as memory access is on an architectural level, it's typically very hard to notice as a user.. I hate trade-offs :p.

Now I just got to decide if all her crap can fit on 4GB o_O.

EDIT:
Thx :)
 
Modern chipsets can do asymmetric dual channel. In this case the first 4gb is dual channel and the remaining 2gb runs as single channel, or something like that. It's difficult to find details, and it's been a long time since I've looked into it. You won't notice a difference in speed, though.

I've been running 6gb in my MBP4,1 for about two years now with no issues at all. There's a huge thread about it somewhere that gets dragged up every once in a while.
 
m85476585 said:
Modern chipsets can do asymmetric dual channel. In this case the first 4gb is dual channel and the remaining 2gb runs as single channel, or something like that. It's difficult to find details, and it's been a long time since I've looked into it. You won't notice a difference in speed, though.

I've been running 6gb in my MBP4,1 for about two years now with no issues at all. There's a huge thread about it somewhere that gets dragged up every once in a while.
Click to expand...

Yeah, if it's running in asymmetric dual channel mode then it uses them both independently, so it won't be running the first 2GB of the second stick interleaved or anything, they'll be completely separate, and slower.

Yeah, I have to agree with you that it's unlikely the difference will be noticeable, as the only thing that will take a hit is large memory reads, and she doesn't do any media editing anymore. Maybe Firefox, though, when she gets her 10,000 tabs open :p).

I'll probably go with the 6GB.
 
My point is that it does in fact interleave the first 4gb. Here's what the Intel PM965 (chipset used in Santa Rosa laptops before ours) says about it:

The (G)MCH supports interleaved addressing in dual-channel memory configurations even when the two channels have unequal amounts of memory populated. This is called Intel® Flex Memory Technology.
Intel Flex memory provides higher performance with different sized channel populations than Asymmetric mode (where no interleaving is used) by allowing some interleaving.
The memory addresses up to the twice the size of the smaller SO-DIMM are interleaved on a 64-B boundary using address bit 6 (including any XOR-ing already used in interleaved mode). Above this, the rest of the address space is assigned to the remaining memory in the larger channel. Figure 7 shows various configurations of memory populations.
Click to expand...
http://www.intel.com/Assets/PDF/datasheet/316273.pdf

The chipset in the 4,1 might be different, but I couldn't figure out which one it is. If it's Intel it's a given that it will also support Flex Memory. If it's Nvidia, I think they have their own implementation of Flex Memory/asymmetric dual channel, but they don't publicize the details (full datasheets are only available for hardware manufacturers).
 
m85476585 said:
My point is that it does in fact interleave the first 4gb. Here's what the Intel PM965 (chipset used in Santa Rosa laptops before ours) says about it:


http://www.intel.com/Assets/PDF/datasheet/316273.pdf

The chipset in the 4,1 might be different, but I couldn't figure out which one it is. If it's Intel it's a given that it will also support Flex Memory. If it's Nvidia, I think they have their own implementation of Flex Memory/asymmetric dual channel, but they don't publicize the details (full datasheets are only available for hardware manufacturers).
Click to expand...

Ah, I didn't know about this Flex tech. Gotcha, thank you.
 
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