What is the RandomX dataset and why is it 2 GB?
The RandomX dataset is a large collection of generated data that your computer’s processor reads while mining Monero. In fast mode, it takes up 2,080 MiB of memory—about 2 GB—to make mining depend on fast access to ordinary computer memory, not just raw calculating power.
What the dataset actually contains
Think of the dataset as a huge reference book filled with computer-generated numbers. It does not contain your wallet, transactions, or a copy of Monero’s blockchain—the shared record of transactions.
RandomX is Monero’s mining algorithm: the rules your computer follows when it tries to earn a mining reward. Monero adopted it on November 30, 2019.
While mining, your processor runs a changing mix of instructions and repeatedly looks up entries in this reference book. Those lookups help produce a hash, a digital result that must meet the network’s difficulty target to count as a valid mining solution.
The dataset is generated from a seed tied to Monero’s blockchain. It changes periodically, rather than being rebuilt for every mining attempt. Miners using the same seed generate the same data.
Why it is about 2 GB
The size is a deliberate hardware trade-off.
Your processor has a small amount of very fast built-in memory called cache. Your computer also has much larger main memory, usually called RAM. The dataset is designed to be too large to fit entirely in ordinary processor cache, forcing miners to use RAM.
That matters because specialized mining chips, called ASICs, can gain enormous advantages when a mining job needs only a narrow set of calculations and little memory. Requiring a large dataset and unpredictable memory access makes building a much faster, cheaper specialized miner harder.
About 2 GB was large enough to create that pressure while remaining manageable for many everyday computers. It is not a magic number that makes specialized hardware impossible. It is part of RandomX’s broader design to favor general-purpose processors, or CPUs.
More precisely, the dataset is 2,080 MiB: 2,048 MiB plus an additional 32 MiB. MiB is a memory unit based on powers of two. That is why “2 GB” is useful shorthand, not the exact allocation.
What that means for your computer
The dataset is generally shared by mining threads within the same mining program. A thread is one stream of work your processor handles. You do not normally need a separate 2 GB dataset for every thread.
Each thread also needs its own working memory, called a scratchpad, of about 2 MiB. For good performance, the usual guideline is roughly 2 MB of L3 cache per mining thread. L3 is one level of the processor’s built-in cache.
You also need memory for your operating system and other programs. Having exactly 2 GB of total RAM is therefore not enough for comfortable fast-mode mining.
Can RandomX run without the full dataset?
Yes. RandomX also has a light mode, which uses a 256 MiB cache and calculates needed dataset entries as it goes.
That saves memory but adds substantial work. It is useful for checking mining results, but generally much slower for mining.
In a browser, memory limits and the way the mining software is built can make fast mode difficult. A website showing mining activity does not, by itself, prove your browser has loaded the full RandomX dataset.
The bottom line
The dataset makes access to a large amount of memory part of the mining challenge. Its roughly 2 GB size helps keep ordinary CPUs competitive, but it does not guarantee that your computer—or your browser—will mine profitably.
