Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

feyn-man

macrumors regular
Original poster
Oct 24, 2007
234
0
I don't know what's the mean of "KIT" at some online store of memory, when I want to update my memory of macbook.
Could somebody give me some idea?
 

MIDI_EVIL

macrumors 65816
Jan 23, 2006
1,320
14
UK
I don't know what's the mean of "KIT" at some online store of memory, when I want to update my memory of macbook.
Could somebody give me some idea?


What it means is, if you have two slots, and you want to have a total of 1GB of RAM, a 'kit' would be 2 x 512mb RAM modules which totals 1GB.

For a total of 2GB, a 'kit' would be 2 x 1GB RAM modules.

If you only wanted to upgrade the module in 1 slot, you would want a 'single' module.

A 'kit' is more than one module, a 'single' module is literally a single module.
 

InLikeALion

macrumors 6502a
I believe they're also called 'kits' because it's a 'matched pair.' In most modern machines, if you have matched memory modules, they benefit from dual channel mode. However, buying to singles of the same part numbers will provide the same results, if the computer can take advantage of matched pairs.
 

feyn-man

macrumors regular
Original poster
Oct 24, 2007
234
0
Ok, thank you guys.

But two single 1GB memory will be cheaper than one 2BG kits. Is that weird?
 

diamond.g

Contributor
Mar 20, 2007
10,959
2,349
Virginia
'matched pair tax'? What a strange tax. I have never **** sound that.

It is a saying that I kinda made up on the fly. Kinda like the mythical Apple Tax. Or the "Insert brand name Here" Tax. The matched Pairs tax was really obvious when having memory operate in dual channel mode was more desirable than not. So manufacturers would package memory modules as matched pairs. It also ensured that the overclockability (the other people who cared about the quality of thier ram) was the same between modules.

With Apple systems the only thing you really should worry about is that the memory modules are quality modules. Matched pair isn't as important anymore. Especially since Apples latest systems can't be overclocked (as far as I can tell).
 

feyn-man

macrumors regular
Original poster
Oct 24, 2007
234
0
It is a saying that I kinda made up on the fly. Kinda like the mythical Apple Tax. Or the "Insert brand name Here" Tax. The matched Pairs tax was really obvious when having memory operate in dual channel mode was more desirable than not. So manufacturers would package memory modules as matched pairs. It also ensured that the overclockability (the other people who cared about the quality of thier ram) was the same between modules.

With Apple systems the only thing you really should worry about is that the memory modules are quality modules. Matched pair isn't as important anymore. Especially since Apples latest systems can't be overclocked (as far as I can tell).

Thank you! But I still don't understand.

1.What you mean is that the pair is different with two single one which is totally the same?

2. Did you mean that apple don't operate in dual channel mode?
 

diamond.g

Contributor
Mar 20, 2007
10,959
2,349
Virginia
Thank you! But I still don't understand.

1.What you mean is that the pair is different with two single one which is totally the same?

2. Did you mean that apple don't operate in dual channel mode?

The tolerances of two single memory modules can be different. With a matched pair the tolerances are supposed to be close to the same if not the same. This only matters most when overclocking. To operate in dual channel mode all you need is memory of the same size(density) and speed, I don't believe CAS have to be exactly the same.

As an Apple user it just isn't something that needs to be worried about. If you can get the singles cheaper, go for the singles. If Apple ever allowed a means to overclock their systems then we could get into long conversations about what RAM to get.


[begin rant]
As when overclocking you are generally raising the FSB to crazy high speeds. Currently the base speed of the RAM used in MB and MBP's is 266Mhz and 200 for the processor (not sure why it isn't 1:1). Then multiply the memory base by two and the processor rating by 4 to get the final bus speeds. To get the processor speed you then multiply the multiplier by the final bus speed for the processor. When overclocking you can lower the multiplier but not raise it, in all but the Extreme Processors. So to compensate people lower the multiplier and raise the fsb. The average OC for an Intle rig sits somewhere at 400mhz base fsb speed. With a lower multiplier you can see 3.2+ghz speeds out of a 2.6ghz processor. With the C2DE line you can see 4+ Ghz with a little water. With LN2 people have been seeing what 5+ Ghz... Oh, I didn't even get into VDD...[end rant]
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
18,350
2,760
Not all RAM vendors charge extra for a kit versus two single sticks...in fact, two of the most frequently recommend ones here don't. DMS charges exactly double the single stick price for a kit, while OWC actually gives you a break of a buck or two when you buy a kit over two single sticks.
 

InLikeALion

macrumors 6502a
Thank you! But I still don't understand.

1.What you mean is that the pair is different with two single one which is totally the same?

2. Did you mean that apple don't operate in dual channel mode?

1) I don't think their is a difference, at least in the real world. Two modules of the same part number should work just fine. Matched pairs seems to be little more than marketing and paying a 'tax' for intangible 'peace of mind'

2) Many macs (maybe all current?) are able to use dual channel mode. Dual channel doesn't specifically have to do with overclocking, and certainly isn't reliant on it. (It sounds to me they were thinking of ECC error checking, which is more expensive and needed for over-clocking. Since macs don't allow for ram over-clocking, then its fine to get non-ECC ram)

Edit: diamond.g is correct. I was a little off about the ECC comments - that's not what he was talking about.
 

kaiwai

macrumors 6502a
Oct 21, 2007
709
0
Christchurch
Ok, thank you guys.

But two single 1GB memory will be cheaper than one 2BG kits. Is that weird?

Strange, depends on the brand. In the past I have found that at times the pair'ed version is cheaper, or around the same price as two single. When I upgraded my iMac G5 it came out cheaper to buy a 'kit'.

If you buy single, there is always a risk of no dual channel.
 

feyn-man

macrumors regular
Original poster
Oct 24, 2007
234
0
1) I don't think their is a difference, at least in the real world. Two modules of the same part number should work just fine. Matched pairs seems to be little more than marketing and paying a 'tax' for intangible 'peace of mind'

2) Many macs (maybe all current?) are able to use dual channel mode. Dual channel doesn't specifically have to do with overclocking, and certainly isn't reliant on it. (It sounds to me they were thinking of ECC error checking, which is more expensive and needed for over-clocking. Since macs don't allow for ram over-clocking, then its fine to get non-ECC ram)

Edit: diamond.g is correct. I was a little off about the ECC comments - that's not what he was talking about.

So is there something I have to do to turn on the dual channel mode?
 

Freyqq

macrumors 601
Dec 13, 2004
4,038
181
sometimes it's cheaper and sometimes its more expensive. It's just a marketing thing. You can get a matched pair by buying 2 singles of the same ram too..
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.