Got a new rig - or an older one that hasn't been touched since the day you plugged it in? There's a good chance it's leaving FREE performance on the table.
I see it ALL the time. Someone brings their PC in for a clean & tune, I jump into the BIOS, and their shiny DDR5 6000 kit is crawling along at 4800MHz. Nobody told them there's a switch to flick.
So here are my three must-do's for every gaming PC. None of them cost a cent, and all three take less time than a round of Warzone.
1. Turn on XMP / EXPO
What it is
Your RAM is sold at a certain speed - 6000MHz, 3600MHz, whatever's on the box. But out of the box, almost every motherboard runs it at a slow, "safe" default speed instead. On DDR5 that's usually 4800MHz. On DDR4 it's usually 2133 or 2400MHz.
XMP (Intel) and EXPO (AMD) are profiles stored on the RAM sticks that tell your motherboard "run me at the speed & timings I was actually built for". The catch? You have to turn it on yourself.
Why it matters
Games LOVE fast memory - especially your 1% lows, which are the stutters and dips you actually feel in-game. Running your kit at its rated speed is one of the easiest FPS gains going, especially in CPU-heavy titles. You paid for that speed - use it.
How to turn it on
- Restart your PC and tap Delete (or F2) to get into the BIOS.
- Look for XMP, EXPO - or DOCP on some ASUS AMD boards. On most boards it's right there on the main screen.
- Select Profile 1, then save & exit (usually F10).
Heads up: on DDR5, the first boot after changing memory settings can take a minute or two while the board "trains" the memory. Black screen, fans spinning - that's normal. Do NOT pull the plug. Let it do its thing.
Check it worked
Open Task Manager → Performance → Memory and look at Speed. It should match what's on your RAM box (e.g. 6000 MT/s).
If you get crashes or blue screens after turning it on, update your BIOS first - newer versions often improve memory compatibility. Still not happy? Drop the speed down a notch, or get in touch and I'll sort it for you.
2. Turn on Resizable BAR (ReBAR)
What it is
Normally your CPU can only talk to your graphics card's memory in small 256MB chunks at a time. Resizable BAR lets it access the WHOLE lot at once. AMD calls it Smart Access Memory (SAM) - same thing, different name.
Why it matters
In games that support it, ReBAR can give you a few extra frames and smoother performance. And on some cards it's not optional - Intel Arc GPUs run noticeably worse without it.
You'll need a reasonably modern setup: an RTX 30 series or newer, RX 6000 series or newer, or any Intel Arc card, plus a supported CPU & motherboard (roughly Intel 10th gen or Ryzen 3000 and up, with a few exceptions). Most boards from the last few years support it, sometimes after a BIOS update. Some early RTX 30 cards also needed a GPU firmware update - check your card maker's website if the option won't stick.
How to turn it on
In the BIOS:
- Enable Above 4G Decoding.
- Enable Re-Size BAR Support (on some boards this only shows up once Above 4G Decoding is on).
- Make sure CSM (Compatibility Support Module) is Disabled - ReBAR needs your PC booting in proper UEFI mode.
- Save & exit.
IMPORTANT: If Windows was installed years ago in old "legacy" (MBR) mode, turning CSM off can stop it from booting. If that happens - don't panic. Just go back into the BIOS, turn CSM back on and you're back where you started. Windows has a built-in tool (MBR2GPT) to convert the drive, or bring it in and I'll do it for you.
Check it worked
Grab the free tool GPU-Z and look for Resizable BAR: Enabled. NVIDIA users can also check NVIDIA Control Panel → System Information.
Note: NVIDIA only switches ReBAR on for games they've tested it with. That's normal - the driver handles it for you.
3. Debloat Windows with Chris Titus' WinUtil
What it is
A fresh Windows install comes stuffed with things you never asked for - preinstalled apps, ads in the Start menu, telemetry phoning home and background services chewing up CPU & RAM while you game.
Chris Titus Tech's Windows Utility (WinUtil) is a free, open-source tool that cleans a lot of that up in a few clicks. It's what I point people to when they ask how to clean up their Windows.
How to run it
- Right-click the Start button and choose Terminal (Admin) (or Windows PowerShell (Admin)).
- Paste this in and hit Enter:
irm https://christitus.com/win | iex
- WinUtil will open. Head to the Tweaks tab.
- Click the Standard preset - it's the balanced, sensible option for most people.
- Make sure Create Restore Point is ticked, so you've got an undo button.
- Click Run Tweaks, let it finish, then restart.
Bonus: the Install tab is SUPER handy for grabbing Steam, Discord, your browser and the rest in one go on a fresh install.
My honest advice
- Stick with Standard. The advanced tweaks are for people who know exactly what each one does. Ticking everything is how you end up with a broken Start menu and no Microsoft Store.
- Only ever use the official command above (from christitus.com or Chris' GitHub). Never run scripts you've copied from a random video comment or website.
- Big Windows feature updates can switch some of this stuff back on, so it's worth running again after one.
- WinUtil is a community tool - it's not made by Microsoft, and it's not mine. I just rate it.
The Perfect PC difference
XMP/EXPO is the starting point, not the finish line. On every rig I build, I go further - manually tuning CPU clocks, voltages & RAM timings - and every build leaves here stress tested with Windows set up clean & up to date. Plug it in and you're away.
Got an older rig that's never had any love? A clean & tune will strip out the dust, re-paste the CPU & GPU and get all of the above dialled in properly.
If you have an older machine, a limited budget but want more FPS for your favourite game - get in touch, you might be surprised with how much performance you can get.
Frequently Asked Questions
Is XMP/EXPO safe to turn on?
Yes. It's the speed your RAM was sold, rated and tested at. It does push the memory controller in your CPU a bit harder than stock, so very occasionally a system won't be stable with it - a BIOS update or dropping the speed a notch usually sorts it.
Will Resizable BAR boost FPS in every game?
No. Gains depend on the game and your hardware - some games see a few extra frames, others see nothing. But there's very little downside to having it on, and for Intel Arc cards it's a must.
Is Chris Titus' WinUtil safe?
It's free, open source and widely used by PC gamers. Run it from the official command, stick to the Standard preset and make a restore point first, and you'll be fine.
Can you set all of this up for me in Auckland?
Absolutely. Drop your PC into the workshop in Whenuapai or get in touch - I'll get your RAM, ReBAR and Windows sorted, plus a full tune if it needs one.