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How to find out the MHz on RAM just by looking at it? If it doesn't show it isn't there a mathematical way to fined it?

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As asked, a stick with no clear speed label is hard to identify by sight alone. Several people here (notably and ) pointed to stickers and the BIOS/UEFI — that’s a good start. Below are the practical rules and a short math trick that will let you turn whatever numbers you do find into the RAM’s marketed speed, plus what to watch for so the value you read is the one the system actually uses.

DDR modules are marketed by their effective transfer rate (MT/s) and that number is often written as “MHz” by sellers. Because DDR is double‑data‑rate, monitoring tools or the BIOS often show the physical clock (half the marketed number). In other words: advertised DDR speed ≈ DRAM frequency × 2; if a tool shows 800 MHz the module is commonly sold as 1600 MT/s (sometimes written as 1600 MHz). (en.wikipedia.org)

If the stick shows a “PC” bandwidth label (for example PC3‑12800), convert it with simple math: advertised MT/s = (PC rating in MB/s) ÷ 8. Example: PC3‑12800 → 12800 ÷ 8 = 1600 MT/s (DDR3‑1600). The reverse also works: MT/s × 8 = theoretical MB/s (PC rating). Keep in mind manufacturers sometimes round or use shorthand (PC3‑10600 vs PC3‑10666), so small differences can appear. (crucial.com)

When a stick has no sticker, look for a part number printed on the PCB and look it up, or read the SPD data the module stores (the tiny EEPROM the motherboard reads at boot). SPD lists JEDEC (safe) speeds and any higher XMP/DOCP profiles the maker put on the module — systems boot at JEDEC defaults unless you enable an XMP/DOCP profile in UEFI. If you can’t boot the stick in a board, a simple part‑number lookup is usually the fastest route. For SPD details and how motherboard firmware reads it, see the SPD explanation and XMP overview. (memtest86.com)

Summary: read any PCB part number or PC-rating and use the divide/multiply‑by‑8 trick; remember BIOS/tools may show half the advertised number (physical clock), and the module may run at lower JEDEC speeds until an XMP profile is enabled.

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Member Avatar for caperjack

how much MHz a RAM has

you how much it is ,not has ,as the Mhz is speed of ram not size .,like the older 100,133,300-400,800,ect ect if it aint on the sticker im not sure how to find the mhz with out putting it into a computer and using a program like cpuid cp-z software
if the ram has a model/make numbwer on it you could google to find info
cpuid tool
Click Here

Edited by caperjack
Member Avatar for javanoob101

usually, it's got a sticker on the ram chip itself, otherwise your BIOS may list the speed it's currently working at

javanoob101

Member Avatar for ssahilk

usually, it's got a sticker on the ram chip itself, otherwise your BIOS may list the speed it's currently working at

javanoob101

Member Avatar for KillerQuag

I've been a fan of Speccy by Piriform.com Shows all your hardware details.

Member Avatar for Little Relhok1

Try CPUID. I haven't tried Speccy but I will now.

Member Avatar for Little Relhok1

Just tried Speccy. I like the interface better. Thanks.

Member Avatar for helenspencer

The unit mentioned by you MHZ is the speed of the RAM and not the size of RAM if you need to nkow the size of RAM means then please right click on computer and properties in that oyu can se the size of RAM memory

Member Avatar for MadeIT

there are a lot programms such as CPU-Z, aida and everest. They can help to investigate everything that have something incommon with your hardware, not only ram.

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