ComputersAll-in-One Desktop
Lenovo 13AT Computer Manual
Setup, everyday use, maintenance and troubleshooting for the 23.8 in. all-in-one desktop, with verified specifications.
- ProcessorIntel Core Ultra 9 285
- Memory64 GB
- Screen23.8 in.
- Est. yearly cost$13.18
About the Lenovo 13AT
Lenovo model 13AT is a 23.8 in. all-in-one desktop that meets ENERGY STAR computer efficiency requirements. It is also identified as ThinkCentre M90a Gen 6.
The certified configuration includes an Intel Core Ultra 9 285 processor (24 cores, up to 5.6 GHz), 64 GB of memory, SSD storage across 2 drives, and discrete graphics, running Windows 11. It also has a dedicated neural processing unit (NPU) for on-device AI features. Retail configurations of the same model can differ, so check the system information on your unit.
Hardware listed in the certification record includes a 23.8 in. touch display (2.07 megapixels), a 230 W internal power supply (94% efficient at half load), and a Gigabit Ethernet port.
Its typical energy consumption (TEC) is 77.5 kWh per year, 32% below the ENERGY STAR limit of 115 kWh for its configuration. Measured idle power is 24.6 W, and sleep draws 1.3 W.
Specifications
| Brand | Lenovo |
|---|---|
| Model number | 13AT |
| Model name / series | ThinkCentre M90a Gen 6 |
| Computer type | All-in-One Desktop |
| Processor | Intel Core Ultra 9 285 |
| CPU cores | 24 |
| Base clock speed | 2.5 GHz |
| Maximum clock speed | 5.6 GHz |
| Neural processing unit (NPU) | Yes |
| Memory (as certified) | 64 GB |
| Storage type | SSD |
| Installed storage drives | 2 |
| Discrete graphics | Yes |
| Operating system | Windows 11 |
| Built-in display (diagonal) | 23.8 in. |
| Display resolution | 2.07 megapixels |
| Touch screen | Yes |
| Internal power supply rating | 230 W |
| Power supply efficiency at 50% load | 94% |
| Gigabit Ethernet ports | 1 |
| Energy Efficient Ethernet | Yes |
| Wake-on-LAN (as shipped) | Enabled |
| Default low-power mode | Sleep |
| Sleep timer (as shipped) | 25 min |
| Display-off timer (as shipped) | 10 min |
| Short-idle power | 24.6 W |
| Long-idle power | 8.2 W |
| Sleep power | 1.3 W |
| Off power | 0.7 W |
| Typical energy consumption (TEC) | 77.5 kWh/yr |
| ENERGY STAR TEC limit | 114.5 kWh/yr |
| Below ENERGY STAR limit | 32% |
Safety information
- Connect the computer to a grounded outlet, preferably through a surge protector. Replace a damaged power cord before further use.
- Lift an all-in-one by the base and frame, not by the screen. Keep the stand on a stable surface so the unit cannot tip when the display is tilted.
- Keep liquids away from the keyboard and vents. If liquid is spilled, shut down immediately, unplug the power and let the computer dry completely before restarting.
Setup
- Unpack and inspect
Remove all packaging, protective film and cardboard inserts. Keep the box and receipt until you are sure the computer works correctly.
- Choose a location
Place the computer on a stable surface or the floor with at least 4 in. (10 cm) of clearance around the vents. Avoid enclosed desk cabinets and carpet, which restrict airflow and collect dust.
- Connect peripherals and network
Connect the keyboard, mouse and any USB devices. For the most reliable connection, plug an Ethernet cable into the network port. Then connect the power cord.
- Complete operating system setup
Follow the Windows setup screens to choose your region, connect to Wi-Fi and sign in. Then open Settings > Windows Update and install all available updates, including optional driver and firmware updates.
- Update firmware and drivers
Use the manufacturer's update utility or support page to install the latest BIOS/UEFI firmware, graphics driver and chipset drivers. Keep the computer plugged in during firmware updates.
- Set up backups
Turn on cloud sync or connect an external drive and schedule automatic backups before you store important files on the computer.
Using your computer
Sleep and power settings
As shipped, the Lenovo 13AT turns off its display after 10 minutes of inactivity and goes to sleep after 25 minutes. Keeping these timers short is the easiest way to save energy. Its default low-power state is conventional sleep, which keeps your session in memory at very low power and resumes in a few seconds. Measured sleep power is 1.3 W, compared with 24.6 W when idle with the screen on.
Performance
The NPU runs AI features such as background blur, live captions and noise suppression with far less power than the CPU or GPU. Keep the NPU driver current to use these features. Discrete graphics (192 GB/s frame-buffer bandwidth, as certified) accelerate games, 3D and video work but add to power draw. With 64 GB of memory, the system has ample headroom for heavy multitasking, large photo or video projects and virtual machines. Solid-state storage needs no defragmenting; leave 10–20% of the drive free so it can maintain performance.
Networking
The computer has one Gigabit Ethernet port. Energy Efficient Ethernet (IEEE 802.3az) lowers link power during quiet periods when the switch also supports it. Wake-on-LAN from sleep is enabled as shipped; IT departments use it to wake computers remotely for overnight updates.
Care and maintenance
| When | What to do |
|---|---|
| Weekly | Restart the computer to apply pending updates and clear memory; confirm that backups completed. |
| Monthly | Install operating system and application updates. Wipe the screen, keyboard and mouse with a soft, slightly damp microfiber cloth (power off first). |
| Every 3–6 months | With the computer shut down and unplugged, clear dust from the front and rear vents. |
| Every 6–12 months | Check for BIOS/UEFI firmware updates from the manufacturer and review storage health and free space. |
Troubleshooting
Start with the simple checks below. For beep codes, diagnostic lights or error messages specific to this model, use the manufacturer's built-in diagnostics and support documentation.
| Problem | Possible cause | What to try |
|---|---|---|
| Will not turn on | Power cord or outlet; power strip switched off. | Check the outlet and power strip, reseat the power cord, then hold the power button for 15 seconds and try again. |
| Runs hot or the fan is loud | Dust-clogged vents; blocked airflow; heavy background task. | Clean the vents, keep 4 in. of clearance around the case, and check Task Manager for apps using a lot of power. |
| Slow performance | Too many background apps; storage nearly full; pending updates. | Close or disable unneeded startup items, free up storage space, install updates and restart. |
| Will not wake from sleep | Software or firmware issue; accessory preventing wake. | Press the power button briefly; update chipset, graphics and firmware; disconnect USB devices to test. |
| Wi-Fi drops or is slow | Weak signal; outdated software; router issue. | Move closer to the router, update the network driver, and restart the router. |
Energy use and running costs
The Lenovo 13AT has a typical energy consumption (TEC) of 77.5 kWh per year, about $13.18 a year at $0.17 per kWh. TEC combines the measured off, sleep and idle power with ENERGY STAR's standard assumptions about how many hours a year a desktop spends in each state. It does not include time under heavy load such as gaming, rendering or video export, which can draw several times the idle figure.
| Power state | Measured power |
|---|---|
| Short idle (on, screen on, nothing running) | 24.6 W |
| Long idle (display off) | 8.2 W |
| Sleep | 1.3 W |
| Off (plugged in) | 0.7 W |
Sleep settings matter: leaving the computer on and idle for the 16 hours a day you are not using it adds about 144 kWh ($24.42) a year, versus 7.59 kWh ($1.29) if it sleeps during those hours.
Frequently asked questions
What processor and memory does the Lenovo 13AT have?
The certified configuration has an Intel Core Ultra 9 285 processor with 24 cores (up to 5.6 GHz) and 64 GB of RAM. Other retail configurations may differ.
How much electricity does the Lenovo 13AT use?
Its ENERGY STAR typical energy consumption is 77.5 kWh per year — about $13.18 at $0.17/kWh. It draws 24.6 W at idle and 1.3 W in sleep.
What size is the Lenovo 13AT screen?
It has a 23.8 in. touch display with a resolution of about 2.07 megapixels.
What operating system does the Lenovo 13AT run?
It was certified with Windows 11.
Does the Lenovo 13AT have an NPU for AI features?
Yes. The certification record lists an installed neural processing unit, which runs on-device AI features efficiently.
Sources and disclaimer
Specifications on this page come from the ENERGY STAR certified computers dataset published by the U.S. Environmental Protection Agency (record certified March 13, 2025), retrieved October 7, 2026.
The setup, operating, maintenance and troubleshooting guidance is written by ManualHarbor's editors for this specific product type and configuration. It is an independent guide — not a reproduction of the manufacturer's manual — and ManualHarbor is not affiliated with Lenovo. Always follow the safety instructions, installation requirements and warranty terms supplied with your unit, and contact Lenovo or an authorized service provider for warranty repairs and replacement parts.
Running-cost figures use assumed U.S. average utility prices and are estimates for comparison only. See our editorial methodology for details.
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