How we check

Every answer on this site comes from hardware reports of real machines, 221,414 of them, plus the ratings makers certify with ENERGY STAR. That covers 17,042 laptops, 5,914 desktops and 5,438 motherboards from 966 makers. Nobody guesses a number. When the reports disagree, the page says so, and a part with no evidence gets no answer.

Where the facts come from

When someone runs a hardware probe on their computer, it records two things we use. The first is the table the firmware keeps about the machine: each memory slot, empty or filled, with the size, type, speed and shape of the stick in it, the battery's design capacity and pack code, the processor and its socket, and the expansion slots the firmware lists. The second is the list of devices on the machine's PCI bus, which shows the SSD controller, the speed of the slot it sits in, and any graphics card. We read both report by report and count them per model. Product strings that name the same machine, such as the Lenovo type codes 20L50000UK and 20L5CTO1WW, are added together on one page.

For the newest models, which the reports haven't reached yet, we use the U.S. EPA's ENERGY STAR certification data: the charger and power supply ratings, battery capacity and memory each certified configuration ships with.

How a memory answer is made

For each report we note how many slots the machine has, whether some memory is soldered to the board, the stick size (laptop-size SO-DIMM or full-size DIMM) and the memory type. Reports that match on all four count toward the same layout.

• A yes or no needs agreement. A page gives a firm answer only when at least 60% of its reports show the same layout. Below that, it says the answer depends on the configuration.
• Few reports are labelled. A model gets a page from one report. Pages resting on one or two machines say so and ask you to check the label before buying.
• Empty tables don't count. Some firmware leaves the memory table out, or lists sockets with nothing in them. A machine can't run on no memory, so those reports say nothing about the slots and aren't counted. They never turn into "soldered".
• Laptops take laptop-size sticks. Laptop firmware often labels its SO-DIMM sticks as DIMM, the desktop size, so on laptops we count both as SO-DIMM.
• Listed sockets aren't always real. Many laptops list four memory sockets and have two. When a laptop lists three or more but no machine in the reports has more than two sticks in it, the page says "at least 2". Workstations that hide two slots under the keyboard can fall in this group, which is why it says "at least".
• Same memory in every machine. Some laptops report soldered memory as a stick in a slot. When six or more machines of a laptop model all have exactly the same total, nobody has ever changed it, so the page asks you to check before you buy instead of suggesting a stick.
• Two cases, two answers. Some desktops were sold as a tower and as a micro case under one name. When at least 10% of reports show the other stick size, the page shows both, with a switch. When the smaller case reports the same stick label but fewer slots, the page warns you with the count.
• Registered memory is named. Workstations and servers built for registered (buffered) ECC sticks don't take ordinary desktop sticks. When half the machines run registered sticks, the page and its Amazon search say registered ECC.
• Speed is the speed the machine runs. We use the speed the firmware configures, not the stick's rated speed: a laptop that runs memory at 2400 can take a 2666 stick, but 2400 is its speed. Old firmware that reports the clock instead of the rate (800 for DDR3-1600) is corrected, and a speed without a known memory type isn't shown.
• Most memory seen working is the largest total installed in at least two machines. A bigger total seen in one machine is mentioned on its own. It can be higher than the maker's printed maximum, because makers list the stick sizes sold at launch.
• The firmware's maximum is shown, labelled as the firmware's claim. It is often wrong: a Dell Latitude 5420 reports a 128 GB maximum, while the most any reported machine runs is 64 GB.

Macs

Mac firmware reports soldered memory as two slots, so the reports alone can't tell a MacBook Air from a 2012 MacBook Pro. We keep a table of Intel Mac model identifiers, written from Apple's memory specification pages, that says which Macs have memory sockets, which have sockets inside the case (Apple calls those a service upgrade) and which have it soldered. The slot count, memory type, speed and amounts still come from the reports. Macs with Apple chips have the memory inside the chip; nothing there can be upgraded.

SSD

• Drive type. When at least 30% of a model's machines have an NVMe drive on the PCI bus (15% and three machines on a laptop), the page says it takes an NVMe M.2 SSD. A few NVMe drives in a model that mostly has none are adapter cards, and those don't count. Intel RAID mode hides NVMe drives, so those reports are left out of the share.
• Slot speed. We read the link the slot itself offers, from the port the drive sits on, so a PCIe 4.0 slot shows as 4.0 even with an older drive in it. The page gives the speed most machines show (60% or more), or both when they differ. A ThinkPad T480 shows PCIe 3.0 x2, a slower slot than most.
• Number of slots. Two drives in one machine prove two slots when at least 15% of the model's NVMe machines run two; a few machines with a second drive are usually running it on an adapter. On motherboards we also use the firmware's own count of M.2 sockets. Laptop and prebuilt firmware lists sockets the board doesn't have (a Legion Go lists two and has one), so there it only proves one. Every count is a floor, so the page says "at least".
• Older desktops. Desktops from before 2016 run NVMe drives on PCIe adapter cards, which aren't M.2 slots, so they need the firmware to list an M.2 socket.
• SATA drives. When none of at least three machines of a laptop runs an NVMe drive and most have a SATA controller, the page says it takes a SATA SSD: a 2.5-inch drive, or in thin laptops a small mSATA or M.2 SATA card, so check the one you have. Desktops and motherboards with a SATA controller in most machines take 2.5-inch SATA drives beside any M.2 slot.
• No evidence. When the reports show neither, the page tells you how to read the drive you have instead of guessing.
• Length. The reports can't see a drive's length. For a few handhelds (Steam Deck, ROG Ally, Legion Go) we give it from the maker's spec page. Everywhere else the page asks you to check the length printed on your current drive.
• Macs use Apple's own SSD connector, so they get no SSD answer.

Battery

We take the design capacity each battery reports, in watt-hours. Capacities within 2 Wh of each other count as one, and a capacity is listed when at least 10% of the readings show it. A model gets a battery answer only when at least 40% of its reports include a reading. The printed label can read 1 to 3 Wh higher than what the battery reports.

Laptops from before 2013 get no capacity: most of them now run replacement packs whose capacity isn't the maker's. Laptops that run on two batteries at once are left out too, because the reports don't say which battery is which.

When we have no capacity, the page shows where the capacity and part number are printed. Machines that report two batteries (usually one built in and one you can swap) are flagged, so you check which one you are replacing.

The battery also reports its own pack code. When most readings agree, the model shipped with a single battery size, and the code has the shape of that maker's pack or part numbers (HP's HT03XL family, Dell's five-character parts, Lenovo's FRU numbers, ASUS's C31N codes and so on), the page shows it and searches Amazon by it. Placeholder names such as "Smart Battery" are dropped.

Charger and power supply

The reports don't describe the charger. The watts come from ENERGY STAR: makers certify each configuration with a charger, and the page lists every rating certified under that model name. Some configurations ship with a different charger than the one tested, so the page asks you to check the label on yours. A model name only takes these ratings when the certification is from within two years of the model's first firmware, because makers reuse names (there is a 2015 and a 2024 Dell XPS 13 9350). Where we have no rating, the page shows how to read the label on your charger.

Desktop power

Power supply and power adapter ratings come from ENERGY STAR only, so they cover desktops certified from about 2020. The firmware also has a power supply record, but checked against the makers' data sheets it was wrong (Fujitsu ESPRIMO P910 and E720 firmware says 240 W, the data sheets say 280 W) or named one of several units (a Lenovo ThinkStation P500 shipped with 490, 650 or 850 W), so we don't use it. Every other desktop page shows where the rating is printed: on the supply's sticker inside the case, or on the adapter for mini PCs. Prebuilt desktops often use a supply shaped for their case, so the page asks you to match the shape and the plugs as well as the watts.

Processor and graphics card

For motherboards and tower or small desktops, the page lists the processors in the reports with how many machines run each one, and the socket when the firmware names it and 60% of reports agree. A newer processor for the same socket can need a BIOS update, and prebuilt desktops often only take the generation they shipped with. Graphics: the number of full-length (x16) slots the firmware lists, as "at least" because some firmware lists a full-length slot by its slower wiring (and a second x16 slot often runs at x4), and for prebuilt desktops, the graphics cards seen in the reports. When some machines report a small case, the page warns that small cases take low-profile cards only. When the firmware lists no slots or socket, the page says what to look for instead.

What we leave out, for now

• SSD length on most models, drive bays, charger plugs, and power ratings for desktops older than about 2020. No source describes these model by model, so the page shows you where to read them on your own machine.
• Macs with Apple chips. Nothing inside them can be upgraded, and their reports carry no memory table.
• Virtual machines, test boards and servers. Reports from hypervisors, chip makers' reference boards and server boards aren't computers you can buy, so they are filtered out.

Before you buy

Check the model name and type code on the label of your machine first. Laptops that share a name can differ between type codes, and the page tells you which code it covers. The buttons open an Amazon search for the exact type, speed, size or pack code. We don't show prices, because they change by the hour.

Sources

The hardware reports come from the Linux Hardware Database, published as linuxhw/DMI (firmware tables) and linuxhw/LsPCI (PCI devices) under the Creative Commons Attribution 4.0 licence. PCUpgradeDex changed the data: we joined the two by machine, merged product strings that name the same machine, filtered out virtual machines, reference boards and servers, and turned the per-report tables into the answers on this site with the rules above.

Charger, power supply and battery ratings for the newest models come from the U.S. Environmental Protection Agency's ENERGY STAR Certified Computers data, snapshot of 10 Nov 2026. ENERGY STAR doesn't endorse this site. Mac model names and which Macs have memory sockets come from Apple's memory specification pages; SSD lengths for handhelds from the makers' spec pages.

The answers are ours; any mistakes in them are ours too.

Data last rebuilt 10 Nov 2026.