search technology reviews, news, features, group tests
Popular Searches:   free , windows , video
Mobile Edition  | 
 |  Register
 |  Newsletters  | 
Sitemap  |  RSS
RSS
Sunday November 29, 2009 7:11 AM AEST
Skip Navigation LinksPC Authority > Features > Does faster RAM really make a difference?
Does faster RAM really make a difference?
«»
FEATURE

Does faster RAM really make a difference?

by Darien Graham-Smith  on Nov 17, 2008
Tags: RAM | memory

What sort of modules should I choose?
Unless your computer is a real antique, buying RAM means buying DIMMs: dual in-line memory modules. DIMMs come in several types, and which sort you need depends on your motherboard. If your computer’s more than four years old, it might take plain old DDR DIMMs (known as “double data rate” because memory can be accessed twice per clock signal). More recent PCs will most likely use the faster DDR2 DIMMs, while high-end desktop systems might use the latest DDR3 standard.

The different types of DIMM aren’t cross-compatible: if your motherboard demands DDR2, it won’t work with DDR3. To ensure you don’t make mistakes, different types of DIMM have notches in different places, making it impossible to plug the wrong sort of DIMM into a slot. To find out which type of DIMM you need, look at the modules already installed on your PC: odds are they’ll be labelled either DDR, DDR2 or DDR3. Alternatively, go online and look up your motherboard on the manufacturer’s website, or use a system-analysis tool such as SiSoft Sandra.

A few motherboards based on Intel’s P35 and P45 chipsets provide slots for both DDR2 or DDR3, offering some flexibility. Be warned, though: you can’t use both types at once.

If you have a laptop, you’ll need to use compact modules known as “small outline DIMMs”, or SODIMMs. As with desktop modules, SODIMMs come in DDR and DDR2 flavours, with notches to ensure they’re only plugged into the right sort of slot. DDR3 SODIMMs are starting to appear on the market too, though only the very newest laptops use them.

Is there an optimum number of DIMMs?
We tend to think of a computer’s memory as a contiguous space, but in the physical world it’s normally spread across multiple DIMMs, filling up some or all of the motherboard’s slots. This raises a few practical and technological issues.

One obvious consideration is how many memory slots your motherboard has. Most come with four DIMM slots, though a few have six or even eight, while lightweight systems and laptops often have only two. If you have just two slots free, it makes little sense to fill them with two low-capacity DIMMs, as you’ll be closing off options for future upgrades. Due to the dynamics of supply and demand, it may not make economic sense, either: a pair of 512MB DIMMs can cost more than twice as much as a single 1GB module.

However, two smaller DIMMs can be faster than one large one – as long as your motherboard supports dual-channel architecture. This is a similar system to RAID0 striping, but for memory rather than hard disks: two identical DIMMs run in parallel, acting as one large module with twice the bandwidth of a normal DIMM.

To quantify the benefits of dual-channel architecture, we tried our standard benchmarks with a single 2GB DIMM, then repeated them with two 1GB DIMMs in dual-channel mode. You can see the results in the bottom-left graph on page 102.

We found the benefits varied hugely between apps: dBpoweramp and Photoshop gained no advantage, but Canopus ProCoder completed its tasks 1% more quickly with dual-channel RAM, while 3ds Max gained a 1.5% boost. Our Office tasks ran a whole 5% faster, and the multi-applications test reflected a 3% performance improvement.

If your motherboard supports dual-channel operation, the DIMM slots will be colour-coded in pairs. To take advantage of it, you simply need to install two identical modules in slots of the same colour – which is one reason why DIMMs are often sold in matched “kits”. You may also have to enable dual-channel architecture in your BIOS.

Copyright © 2009 Dennis Publishing
This article appeared in the December, 2008 issue of PC Authority.
«»
Email a Friend Email this
Print Page Print this
Tweet This Tweet this
Feedback Send us your tips


Ads by Google

Comments

Be the first to comment on this article.
Thoughts on this article? Add a comment below.
Login or register to submit a comment.
 

Top Stories

All I want for Christmas...Apple slapping on the discount stickers this Friday
If you're looking to buy an Apple product then this Friday is your lucky day, with Apple planning a "Black Friday" discount frenzy.
 
Telstra release slew of new plans, Earth fails to shake
New broadband plans from Telstra with bigger download quotas are welcome, though you'll still find better value with the competition
 
TiVo 2.0: Revamped content line-up could fuel box bust-up for pay TV competition, as IPTV era begins
TiVo have doubled their drive capacity, introduced IPTV capabilities, vast amounts of new content and better home networking options. But can the marketplace handle another content provider?
 


 
Intel
 
Popular
Most Discussed
PC Authority Featured Retailers
hot bargains from the mwave store
City Software, Australia's online computer store with up to 80% off RRP
special offers from dell
Special promotions from the Apple store - Redeem here
PC Authority Featured Retailers
 
LogMeIn
 
 
Amazing Dell Coupons now available
 
Discover Apple
 

Plan Finder

Powered by WhistleOut

1) Apple iPhone 3GS 16GB35 plans 21%
2) Apple iPhone 3GS 32GB35 plans 2%
3) Blackberry Bold 900014 plans 3%
4) Nokia N9742 plans 7%
5) Blackberry Curve 85206 plans 14%
Three Virgin Mobile Vodafone
« 1 of »
1) iiNet32 plans 1%
2) Netspace33 plans 2%
3) Optus47 plans 5%
4) Internode34 plans 7%
5) Telstra BigPond41 plans 8%

Compare: Mobiles | Broadband

PC Authority