Buying Guide
The Best $900 Mini-ITX Office PC Build
Six parts for a Mini-ITX office PC, each checked against the others for socket, memory, power and case fit.
By The PC Journal editorial team
12 min read6 products evaluated
A Mini-ITX office PC trades expansion for size, so its parts list is tighter than a mid-tower's: two memory slots, one graphics slot and a case picked for the supply it takes. Every part is on AM5 with DDR5, the Ryzen 5 8600G drives the monitor with its integrated graphics, and the Thermaltake Tower 250 lists support for an ATX or SFX power supply, so a standard ATX unit fits.
This is a research build, not a lab build: the parts were picked from the makers' figures and then checked against each other, beginning with CPU socket, memory type and memory kit. The total fell between $850 and $900 when we checked.
Quick Picks
Our 6 recommendations at a glance. Tap a pick for the full verdict.
Processor
AMD Ryzen 5 8600G
Radeon 760M integrated graphics.
Best for: Buyers assembling a Mini-ITX office PC who care about Radeon 760M integrated graphics.
Our take Check price for AMD Ryzen 5 8600G (opens in a new tab)
Motherboard
ASRock B650I Lightning WiFi
PCIe 5.0 M.2 slot.
Best for: Buyers assembling a Mini-ITX office PC who care about PCIe 5.0 M.2 slot.
Our take Check price for ASRock B650I Lightning WiFi (opens in a new tab)
Memory
CORSAIR Vengeance RGB RS 16GB (2x8GB) DDR5-6000
ICUE lighting control.
Best for: Buyers assembling a Mini-ITX office PC who care about iCUE lighting control.
Our take Check price for CORSAIR Vengeance RGB RS 16GB (2x8GB) DDR5-6000 (opens in a new tab)
Storage
Kingston NV3 500GB
M.2 2280 NVMe drive.
Best for: Buyers assembling a Mini-ITX office PC who care about M.2 2280 NVMe drive.
Our take Check price for Kingston NV3 500GB (opens in a new tab)
Power Supply
Thermaltake Smart BM3 650W
Japanese 105°C main capacitor.
Best for: Buyers assembling a Mini-ITX office PC who care about japanese 105°C main capacitor.
Our take Check price for Thermaltake Smart BM3 650W (opens in a new tab)
Case
Thermaltake Tower 250
GPUs up to 360mm with the power cover removed.
Best for: Buyers assembling a Mini-ITX office PC who care about GPUs up to 360mm with the power cover removed.
Our take Check price for Thermaltake Tower 250 (opens in a new tab)
| Pick | Why it’s here | Best for | Price |
|---|---|---|---|
| Radeon 760M integrated graphics. | Buyers assembling a Mini-ITX office PC who care about Radeon 760M integrated graphics. | Check price for AMD Ryzen 5 8600G (opens in a new tab) |
| PCIe 5.0 M.2 slot. | Buyers assembling a Mini-ITX office PC who care about PCIe 5.0 M.2 slot. | Check price for ASRock B650I Lightning WiFi (opens in a new tab) |
| ICUE lighting control. | Buyers assembling a Mini-ITX office PC who care about iCUE lighting control. | Check price for CORSAIR Vengeance RGB RS 16GB (2x8GB) DDR5-6000 (opens in a new tab) |
| M.2 2280 NVMe drive. | Buyers assembling a Mini-ITX office PC who care about M.2 2280 NVMe drive. | Check price for Kingston NV3 500GB (opens in a new tab) |
| Japanese 105°C main capacitor. | Buyers assembling a Mini-ITX office PC who care about japanese 105°C main capacitor. | Check price for Thermaltake Smart BM3 650W (opens in a new tab) |
| GPUs up to 360mm with the power cover removed. | Buyers assembling a Mini-ITX office PC who care about GPUs up to 360mm with the power cover removed. | Check price for Thermaltake Tower 250 (opens in a new tab) |
Our Picks
Processor1 of 6
AMD Ryzen 5 8600G on Amazon (opens in a new tab)
The Ryzen 5 8600G pairs six cores with Radeon 760M graphics.
Best for
- Buyers assembling a Mini-ITX office PC who care about Radeon 760M integrated graphics.
Skip if
- Skip it if 6 cores leave less headroom for streaming alongside games.
Why we like it
It can run a PC without a graphics card until you buy one.
The Ryzen 5 8600G brings 6 cores and 12 threads, a 5GHz maximum boost, 16MB of L3 cache and a 65W rating, and it accounts for 21% of the parts total. A cooler comes in the box, so the build adds none. Its integrated graphics drive the monitor, so no graphics card is needed.
The Ryzen 5 8600G uses the AM5 socket and the B650I Lightning board uses AM5, so the processor seats in the board directly. Read the board's CPU support list for the BIOS version this chip needs. DDR5 is what the B650I Lightning and the Ryzen 5 8600G share, and the Vengeance RGB RS 16GB kit is DDR5. The two memory generations do not fit each other's slots, so this is a hard match rather than a preference. Integrated graphics on the Ryzen 5 8600G drive the display through the B650I Lightning's own HDMI or DisplayPort, so there is no card to buy; match the port to your monitor's input first. To spend less, the Ryzen 5 8500G is 6 cores against 6, roughly 22% cheaper than the Ryzen 5 8600G; the socket, memory and cooler checks still pass.
Key dimensions & specs
- L3 cache: 16MB
- Max boost: 5GHz
- Cores / threads: 6 cores
- Rated power: 65W
- Threads: 12
- Socket: AM5
- Memory: DDR5
- Cooler in box: Yes
- Integrated graphics: Yes
Pros
- 65W rating suits a modest air cooler
- Wraith Stealth cooler in the box
- Integrated graphics for display output without a graphics card
- Radeon 760M integrated graphics
Cons
- 6 cores leave less headroom for streaming alongside games
- At 21% of the parts total, a swap here moves the whole budget
Motherboard2 of 6
ASRock B650I Lightning WiFi on Amazon (opens in a new tab)
The B650I Lightning uses the older B650 chipset at a lower price, keeping a PCIe 5.0 M.2 slot and Wi-Fi 6E.
Best for
- Buyers assembling a Mini-ITX office PC who care about PCIe 5.0 M.2 slot.
Skip if
- Skip it if this is a dealbreaker: only 2 M.2 slots.
Why we like it
It suits budget small builds with a mid-range CPU.
For 19% of the parts total, the B650I Lightning adds Mini-ITX size, 2 M.2 slots, Wi-Fi 6E and 2.5GbE LAN on the AM5 socket, and only DDR5 sticks fit its slots.
The Ryzen 5 8600G uses the AM5 socket and the B650I Lightning board uses AM5, so the processor seats in the board directly. Read the board's CPU support list for the BIOS version this chip needs. DDR5 is what the B650I Lightning and the Ryzen 5 8600G share, and the Vengeance RGB RS 16GB kit is DDR5. The two memory generations do not fit each other's slots, so this is a hard match rather than a preference. The B650I Lightning lists 2 M.2 slots, so the NV3 500GB has a home and a second drive can follow. The manual says which slot runs at full PCIe speed.
Key dimensions & specs
- M.2 slots: 2
- Wired LAN: 2.5Gbps
- Wi-Fi: Wi-Fi 6E
- Power stages: 8+2+1
- Form factor: Mini-ITX
- Socket: AM5
Pros
- PCIe 5.0 M.2 slot
- The older B650 chipset at a lower price
- Passes 4 compatibility checks that name it in this build
- Takes 19% of the parts total, and every figure it is checked on is stated in its listing
Cons
- Only 2 M.2 slots
- Wi-Fi 6E rather than Wi-Fi 7
Memory3 of 6
CORSAIR Vengeance RGB RS 16GB (2x8GB) DDR5-6000 on Amazon (opens in a new tab)
Vengeance RGB RS 16GB offers 6000MT/s with both EXPO and XMP profiles and iCUE lighting.
Best for
- Buyers assembling a Mini-ITX office PC who care about iCUE lighting control.
Skip if
- Skip it if 16GB leaves less headroom than 32GB for heavy browser or creative work.
Why we like it
16GB, DDR5, 6000MT/s and EXPO and XMP profiles, sold as two sticks, accounts for 32% of the parts total and shows how pricey DDR5 is right now.
DDR5 is what the B650I Lightning and the Ryzen 5 8600G share, and the Vengeance RGB RS 16GB kit is DDR5. The two memory generations do not fit each other's slots, so this is a hard match rather than a preference. Because the Vengeance RGB RS 16GB is a two-stick 16GB kit, the board manual's dual-channel slot pair is where it goes. To spend more, the Viper Elite 5 is 32GB at 6000MT/s, roughly 64% dearer than the Vengeance RGB RS 16GB; it stays on the generation the board and processor take.
Key dimensions & specs
- Rated speed: 6000MT/s
- Capacity: 16GB (2 sticks)
- Profiles: EXPO and XMP
- RGB: Yes
- Memory type: DDR5
Pros
- 6000MT/s, the usual sweet spot for AM5
- Both AMD EXPO and Intel XMP profiles
- ICUE lighting control
Cons
- 16GB leaves less headroom than 32GB for heavy browser or creative work
- At 32% of the parts total, a swap here moves the whole budget
Storage4 of 6
Kingston NV3 500GB on Amazon (opens in a new tab)
The NV3 500GB stands out for an M.2 2280 NVMe drive.
Best for
- Buyers assembling a Mini-ITX office PC who care about M.2 2280 NVMe drive.
Skip if
- Skip it if this is a dealbreaker: slower 5,000MB/s rated reads.
Why we like it
It also offers a 5,000MB/s rated read speed and is rated for 0.5TB.
The NV3 500GB offers 500GB, PCIe 4.0 and up to 5000MB/s sequential reads and takes 11% of the parts total.
The B650I Lightning lists 2 M.2 slots, so the NV3 500GB has a home and a second drive can follow. The manual says which slot runs at full PCIe speed. If the budget allows more, the NV3 1TB offers 1TB on PCIe 4.0, roughly 57% dearer than the NV3 500GB; the board's M.2 row is unaffected.
Key dimensions & specs
- Sequential read: 5,000MB/s
- Interface: PCIe 4.0 x4
- Capacity: 0.5TB
Pros
- M.2 2280 NVMe drive
- Passes the one compatibility check that names it in this build
- Takes 11% of the parts total, and every figure it is checked on is stated in its listing
Cons
- Slower 5,000MB/s rated reads
- 500GB fills quickly once a few large programs or games are installed
- The listing does not say whether the drive has a DRAM cache
Power Supply5 of 6
Thermaltake Smart BM3 650W on Amazon (opens in a new tab)
The Thermaltake Smart BM3 650W stands out for Japanese 105°C main capacitor, and it adds semi-modular cables: fixed main cables, detachable extras.
Best for
- Buyers assembling a Mini-ITX office PC who care about japanese 105°C main capacitor.
Skip if
- Skip it if this is a dealbreaker: A shorter 5-year warranty.
Why we like it
It also offers a 650W rated output and offers a 5 years warranty.
The Thermaltake Smart BM3 650W is 650W, Bronze rated, ATX 3.1, ATX format and semi-modular cables and takes 7% of the parts total.
The Thermaltake Smart BM3 650W is a ATX unit and the Tower 250 lists SFX or ATX, so the supply has a mount. In the $50 to $100 band, it is the sixth biggest of the six lines, and a different pick would move about 7% of the total.
Key dimensions & specs
- Wattage: 650W
- Warranty: 5 years
- 80 Plus rating: Bronze
- ATX version: ATX 3.1
- Form factor: ATX
- Cabling: Semi-modular
- Fan: 120mm
- Fan stop: Yes
- Colour: Black
Pros
- A 650W rating
- ATX 3.1 compliance
- A fan that stops at low load
- Japanese 105°C main capacitor
Cons
- A shorter 5-year warranty
- Only 80 Plus Bronze efficiency
- Cables that do not fully detach take more routing work in a small case
Case6 of 6
Thermaltake Tower 250 on Amazon (opens in a new tab)
The Tower 250 stands upright and takes a 360mm radiator, rare for Mini-ITX, with an SFX bracket preinstalled and ATX support too.
Best for
- Buyers assembling a Mini-ITX office PC who care about GPUs up to 360mm with the power cover removed.
Skip if
- Skip it if the listing gives no CPU cooler height limit, so check the case page.
Why we like it
Two 120mm fans come fitted on top as exhaust.
The Tower 250 lists room for Mini-ITX boards, a radiator up to 360mm and 2 fans in the box and takes 10% of the parts total.
Mini-ITX is the B650I Lightning's size, and the Tower 250 lists Mini-ITX, so the board has a place on its tray. The Thermaltake Smart BM3 650W is a ATX unit and the Tower 250 lists SFX or ATX, so the supply has a mount.
Key dimensions & specs
- Largest radiator: 360mm
- Fans included: 2
- Motherboards: Mini-ITX
- PSU type: SFX or ATX
Pros
- Fits a 360mm radiator
- GPUs up to 360mm with the power cover removed
- Preinstalled SFX bracket
- Mounts for eight 120mm or five 140mm fans
Cons
- The listing gives no CPU cooler height limit, so check the case page
- At 10% of the parts total, a swap here moves the whole budget
How We Chose
Each pick was assessed across 4 criteria weighted for real-world use.
- Compatibility rules
- Seven rules decide whether these parts work together: CPU socket, memory type, memory kit, M.2 slot for the SSD, board size in the case, display output without a graphics card and power supply format. Every one passes.
- Price at the time of writing
- The parts landed between $850 and $900 together, inside the $900 tier. Prices change daily, so the total can drift.
- Maker figures, not testing
- Specifications come from each maker's listing and the chip makers' published power recommendations; we did not build or benchmark this system.
- Headroom
- The Thermaltake Smart BM3 650W is 650W for a system without a graphics card, well above what its parts draw.
What to Look for in a $900 Mini-ITX Office PC Build
Key buying criteria so you get the right fit the first time.
Platform and upgrade path
Ryzen 5 8600G and B650I Lightning use AM5 with DDR5 memory. AM5 has taken several processor generations, so a later Ryzen can drop into the same board after a BIOS update. Among the 16GB kits we reviewed, the typical DDR5 kit cost about 2.3 times the typical DDR4 kit at the time of writing.
Power supply sizing
The Thermaltake Smart BM3 650W is 650W. With integrated graphics and no card, the processor and drives are the only sizeable loads, so the supply has room to spare.
Case fit
Mini-ITX is the B650I Lightning's size, and the Tower 250 lists Mini-ITX, so the board has a place on its tray.
Cooling
The Ryzen 5 8600G includes a cooler in the box, which is enough at its 65W power; add a tower cooler later only if fan noise bothers you.
Storage
The NV3 500GB is PCIe 4.0 x4 and the B650I Lightning has 2 M.2 slots, so a second drive fits later.
Where the money goes
The three largest lines are memory (32%), processor (21%) and motherboard (19%).
How to Choose a $900 Mini-ITX Office PC Build
Compatibility check
We ran 7 checks on these six parts, and the $900 Mini-ITX Office PC Build passes every one using the figures in the makers' listings. Every row rests on a figure the listings state.
| Check | Parts | Result |
|---|---|---|
| CPU socket | Ryzen 5 8600G + B650I Lightning | Both use AM5. |
| Memory type | Vengeance RGB RS 16GB + B650I Lightning + Ryzen 5 8600G | DDR5 on all three. |
| Memory kit | Vengeance RGB RS 16GB | 16GB in two sticks. |
| M.2 slot for the SSD | NV3 500GB + B650I Lightning | 2 M.2 slots on the board. |
| Board size in the case | B650I Lightning + Tower 250 | Mini-ITX board; the case lists Mini-ITX. |
| Display output without a graphics card | Ryzen 5 8600G | Integrated graphics listed. |
| Power supply format | Thermaltake Smart BM3 650W + Tower 250 | ATX unit; the case lists SFX or ATX. |
Scroll sideways to see every column.
These rows compare published figures only. Before ordering, read the board's BIOS notes and the case manual for anything a listing leaves out.
Where the budget goes
Together the parts landed between $850 and $900 at the time of writing, inside the $900 tier.
| Part | Pick | Share of parts total | Price tier at the time of writing |
|---|---|---|---|
| Processor | Ryzen 5 8600G | 21% | $100 to $250 |
| Motherboard | B650I Lightning | 19% | $100 to $250 |
| Memory | Vengeance RGB RS 16GB | 32% | $250 to $500 |
| Storage | NV3 500GB | 11% | $50 to $100 |
| Power Supply | Thermaltake Smart BM3 650W | 7% | $50 to $100 |
| Case | Tower 250 | 10% | $50 to $100 |
Scroll sideways to see every column.
Swap options that stay compatible
Every swap here was tested against the same rules as the build itself, and none of them forces another part to change.
| If you want to | Swap in | What changes |
|---|---|---|
| Spend less on the processor | Ryzen 5 8500G | 6 cores against 6, roughly 22% cheaper than the Ryzen 5 8600G; the socket, memory and cooler checks still pass |
| Spend more on the processor | Ryzen 7 7700 | 8 cores and 32MB of L3 cache against 6 and 16MB, roughly 20% dearer than the Ryzen 5 8600G; the socket, memory and cooler checks still pass |
| Move to 32GB of memory | Viper Elite 5 | 32GB at 6000MT/s, roughly 64% dearer than the Vengeance RGB RS 16GB; it stays on the generation the board and processor take |
| Double the storage to 1TB | NV3 1TB | 1TB on PCIe 4.0, roughly 57% dearer than the NV3 500GB; the board's M.2 row is unaffected |
Scroll sideways to see every column.
Frequently Asked Questions
Is the Thermaltake Smart BM3 650W enough without a graphics card?
Yes, with room to spare: the Thermaltake Smart BM3 650W is 650W and this build draws power mainly through the processor and drives.
Do I need to buy a CPU cooler?
No. The Ryzen 5 8600G includes a cooler in the box, and the build uses it.
Why DDR5 and 16GB of memory?
DDR5 is what the B650I Lightning and the Ryzen 5 8600G share, and the Vengeance RGB RS 16GB kit is DDR5. The two memory generations do not fit each other's slots, so this is a hard match rather than a preference. Among the 16GB kits we reviewed, the typical DDR5 kit cost about 2.3 times the typical DDR4 kit at the time of writing.
Can I upgrade this build later?
AM5 has taken several processor generations, so a later Ryzen can drop into the same board after a BIOS update. The Tower 250 takes up to a 360mm radiator, and the B650I Lightning has 2 M.2 slots.
What is not included in the total?
Only the six parts above are counted. Windows, a monitor, input devices, tax and shipping are not, so budget for them separately.
Bottom Line
Our $900 build centres on integrated graphics, the Ryzen 5 8600G and the Tower 250; it spends on a Mini-ITX board and DDR5 memory, keeps a standard ATX supply and skips a graphics card.
DDR5 kits are the volatile price in this build, so check the memory listing again on the day you order, and buy a two-stick kit because the board has two memory slots.