Question: I have installed 4GB of PC2-5300 DDR2 memory in my Intel 945PM chipset based laptop but it only reports 3GB. Why?

Read our answer below:

The memory controller found within the Intel 945PM mobile chipset codenamed Calistoga does indeed state support for up to 4GB RAM, this however is where the good news ends. Unfortunately, while this is true it is also a minor error made by Intel. The Intel 945PM mobile chipset cannot address all the 4GB of installed memory if there are other devices in the system also sharing the same memory addressing space (something that is true in every respect). As a result, if you wish to upgrade to 4GB RAM, the practical amount the system will see thus use is around the 3GB mark. This will not change regardless whether you install a 32bit or 64bit Operating System.

For example, if you install 4GB RAM (2x 2GB DDR2 PC2-5300 200pin SODIMM) and your system reports 3GB, 3.25GB, 3.5GB etc. then this is exactly how much memory you'll be able to use. The remaining amount will be invisible. How much your system sees is largely dependant on how much memory your graphics card features as it also needs to share the same addressing space.

Luckily, the successor to the Intel 945PM mobile chipset, namely the Intel PM965 mobile chipset codenamed Crestline supports memory remapping thus can utilise the full 4GB if and when installed.

Learn more about the aspects that limit how much you may upgrade your laptop's memory in part 4 of the Laptop Memory Upgrades Guide.

Would you be interested in viewing other technical laptop memory question topics and answers? If so simply click the button below and choose your desired topic by clicking its title.

Read the Laptop Memory Upgrades Guide to learn about all the aspects you should know when buying laptop memory...

...alternatively discover Where to buy 100% compatible SDRAM, DDR, DDR2 and DDR3 SODIMM memory.

PC3200 400MHz DDR 200-pin SODIMM's

Looking for PC3200 400MHz DDR 200-pin SODIMM's for your laptop? Select the memory upgrade you require below and buy without the hassle!

Need other laptop memory SODIMM's? Simply click a memory type below to view a full list of available SODIMM's...

Kingston laptop memoryCrucial laptop memoryCorsair laptop memoryOCZ Technology laptop memoryPNY laptop memoryHypertec laptop memory
laptop memory for HP laptopslaptop memory for Compaq laptopslaptop memory for Dell laptopslaptop memory for Acer laptopslaptop memory for Lenovo laptopslaptop memory for Toshiba laptopslaptop memory for Asus laptopslaptop memory for Fujitsu-Siemens laptopslaptop memory forFujitsu laptopslaptop memory for Sony laptopslaptop memory for Samsung laptopslaptop memory for Packard Bell laptopslaptop memory for Gateway laptopslaptop memory for Apple laptopslaptop memory for Advent laptopslaptop memory for Medion laptopslaptop memory for MSI laptopslaptop memory for Vobis laptopslaptop memory for Hi-Grade laptopslaptop memory for Alienware laptopslaptop memory for Voodoo laptops
Buy laptop memory at CrucialBuy laptop memory at OfftekBuy laptop memory at MyMemoryBuy laptop memory at NovatechBuy laptop memory at EbuyerBuy laptop memory at Micro DirectBuy laptop memory at DabsBuy laptop memory at SaverstoreBuy laptop memory at PC WorldBuy laptop memory at PC World BusinessBuy laptop memory at PIXmaniaBuy laptop memory at InsightBuy laptop memory at MaplinBuy laptop memory at OyyyBuy laptop memory at MiscoBuy laptop memory at BT Business DirectBuy laptop memory at BT ShopBuy laptop memory at PlayBuy laptop memory at KelkooBuy laptop memory at Zavvi
Copyright © 2009 - 2021 Laptop Memory Upgrades UK - All rights reserved.