Question on Available RAM - Win7 32-bit vs. 64-bit

irobot

New member
Local time
1:04 AM
Messages
11
Hi all -

Why is there a 4gb RAM limit with Win7 32-bit?

I just installed the 64-bit version and now have all of my installed RAM (8Gb) available to the OS.
 

My Computer My Computer

OS
Windows 7 Professional 32bit

My Computer My Computer

Computer type
PC/Desktop
Computer Manufacturer/Model Number
Ignatz Special; 4 speed manual gearbox; factory air conditioning; one of one
OS
Windows 7 Home Premium SP1, 64-bit
CPU
Intel Skylake i5-6600K, not overclocked
Motherboard
AsRock Z170M Extreme 4, micro ATX
Memory
8 GB HyperX DDR4-2666 (2 x 4 GB)
Graphics Card(s)
none; graphics are integrated on CPU
Sound Card
onboard: Realtek ALC1150; external: USB Behringer UF0-202
Monitor(s) Displays
Dell S2340M 23 inch IPS
Screen Resolution
1600 x 900
Hard Drives
System: Crucial MX100 series SSD, 128 GB;
Data: Samsung Spinpoint 103SJ, 1 TB;
Backup: WD Caviar Green WD30EZRX-00D8PB0, 3 TB
PSU
Rosewill SilentNight 500 watt fanless, semi-modular
Case
Antec Solo II
Cooling
Noctua NH-U12S; Noctua F12 intake, Noctua S12A exhaust
Keyboard
Microsoft 200 6JH-00001 USB
Mouse
Dell or Microsoft optical wired; USB
Antivirus
Microsoft Security Essentials and Malwarebytes Premium
Browser
Pale Moon
Other Info
All fans PWM; speeds at idle: CPU circa 500 rpm; intake circa 600 rpm; exhaust circa 600 rpm; CPU temps 27 idle and 47 C load in a warm room (27 C/81 F) when running Intel Extreme Tuning Utility stress test.
For 32 bit operating systems the address length is 32 bits, which only allows 2 ^ 32 (4 294 967 296) addresses. Now, looking at that number it might seem like your operating system should support 4 GB, but all the other hardware such as your graphic card or any other card that contains memory (the video ram in your graphic card) that has internal memory also gets mapped into that address space which subtracts from that 4 Gigs, so if you have a graphic card with 512MB or ram your 4 Gig system would show 3.5 Gigs of usable memory.
 
Last edited:

My Computer My Computer

Computer Manufacturer/Model Number
Home build
OS
Windows 7 Pro x64
CPU
AMD FX 4100 4 Core 3.6GHz AM3+
Motherboard
ASROCK 970 Extreme3
Memory
16GB G.Skill RipjawsX
Graphics Card(s)
Radeon 6850
Sound Card
ASUS Xonar D1
Monitor(s) Displays
ASUS 23" LCD
Hard Drives
SSD 120GB
WD 750GB Black series
WD 640GB Black series
PSU
700W
Case
Antec 100
Cooling
Hyper 212 Plus
Internet Speed
50MB
Back
Top