How this site works

Updated October 4, 2026

In short: listings come from eBay's official API and their data is never more than six hours old, price per gigabyte includes shipping or is left blank, and compatibility figures come only from the vendors' own documents.

Two kinds of data sit behind every page: memory listings taken from eBay, and compatibility data researched from vendor documentation. They are made in completely different ways, and the difference matters when you are deciding how much to trust a number.

Listings come from eBay's official API

RAMindex collects listings through eBay's Browse API, the official interface, under an API licence. It never scrapes eBay's web pages.

Collection runs continuously through the day rather than in one nightly batch, so a listing posted this morning does not wait until tomorrow to appear.

A current sample, not a complete count

The tables show a continuously refreshed sample of eBay's memory listings, not a complete index of them. The Browse API returns at most the first 10,000 results of any one query, and the memory categories hold far more listings than any set of queries can reach.

So the catalogue runs to thousands of listings at a time, kept current rather than complete. Finding the cheapest gigabyte among them is the useful question; claiming to have counted every memory listing on eBay would not be true.

Never more than six hours behind eBay

What you see is a snapshot, never more than six hours behind eBay. Listings older than that are not displayed at all, which is a condition of the API licence RAMindex runs under, and every table says how old its own oldest row is. Listings are kept only as long as the licence allows and are removed after that.

Prices and availability change on eBay all the time. The live price is always the one eBay shows, which is why every listing here links straight to it.

Seller details are not stored

No seller username, no feedback score and no item location. eBay's API licence treats these as personal information, and none of them is needed to rank memory by price per gigabyte. They are discarded the moment a listing is read, so there is nothing held here to leak and nothing to purge.

The only location kept is the country an item ships from, which eBay publishes as a public search filter. It is kept because a module coming from another continent is not as cheap as it looks.

Price per gigabyte includes shipping

Price per gigabyte is the total cost divided by the total capacity: the item price plus shipping, over every gigabyte the listing actually includes. A kit of two 16GB modules is 32GB, not 16.

Blank rather than wrong

If either half of that sum is unknown, the column is left blank. When eBay quotes no shipping cost, usually because it is calculated from a buyer's location that RAMindex does not send, the figure is left out rather than worked out as though delivery were free. A confident number built on a missing cost would sort straight to the top of a page whose whole purpose is "cheapest first".

Lots get the same caution. Some titles quote the price of one module while describing a whole lot, and read carelessly they give a figure many times too good, which lands at the top of the table. Where a title cannot be resolved with confidence, the row is published without a price per gigabyte rather than with a flattering one.

Specifications come from the title

Capacity, speed, form factor, buffering, ECC and part numbers are read from the listing title by fixed rules: the same title always gives the same result, and every rule is covered by tests written against published manufacturer datasheets. No language model is involved anywhere in this process. That is a term of eBay's API licence, and it is also the more reliable choice for a job that has to be reproducible.

A blank field means the title did not say. It is not a default, and the filters treat it that way: a listing that never states its buffering does not quietly become unbuffered.

The rules are corrected as new mistakes turn up, and each correction is applied to the listings already held, not only to new ones. A fix reaches the site at the next collection instead of waiting for the old rows to expire.

Part numbers are the least certain field

eBay's search interface returns no manufacturer part number and no item specifics at all, so a part number here is recovered from the words of the title rather than read from a field. That usually works, because a seller who knows the part tends to type it. But it can go wrong in a way a supplied field could not, and it tends to go wrong in one direction.

A listing that says only “memory for a PowerEdge R730xd” names a machine, and a careless reading would file the machine as though it were a part. So the rules refuse anything that is clearly not a part number: the names of machines, both the ones this site describes and the many more servers, boards, desktops and laptops that turn up in “memory for” titles; units and quantities such as 1.2VDC, 3.0GHz or 8-core; and motherboard model numbers. Where a title names both a machine and a part, the part wins. Where it names no part at all, the row is published without one rather than with the nearest code-shaped word.

Compatibility comes from vendor documents

This is the part that does not come from eBay. eBay can say what a module is; it cannot say whether that module will work in the server you own.

Every machine on this site was researched from the vendor's own documentation: owner's manuals, technical guides, QuickSpecs, product guides and motherboard manuals. A record without a cited document is not published at all. The citations stay with the data whether or not a page prints them, and if you ask, the publisher will send the documents behind any figure here.

Each figure is established twice, independently, from different documents. Where the two readings disagree, the value is dropped, not averaged or settled by picking one. A machine missing a figure is a smaller loss than a machine carrying a wrong one, because the wrong one costs somebody the price of memory that ends up in a drawer.

Three examples of that rule at work:

• No load-reduced capacity is published for a non-xd PowerEdge R720, because Dell's only such figure names the xd model.
• No unbuffered capacity is published for a System x3650 M4, because the product guide and the service guide disagree.
• An EliteBook 840 G6 is recorded at 32GB although the headline of HP's own QuickSpecs says 64, because two HP service guides say 32 and list no larger part. The lowest figure every document agrees on is the safe one to act on. Laptops are researched under the same rule, though their pages are not published yet.

Where a vendor states a condition the data cannot hold, it is written out in words instead:

• A PowerEdge R730 reaches 3TB only with E5-2600 v4 processors.
• A ProLiant DL580 G5 has 16 memory sockets on the board and reaches 32 only with an optional expansion card.
• An R720xd with 3.5-inch drives takes no load-reduced memory at all, at any capacity.

The processor decides memory type and speed

A machine's slot count and maximum capacity come from the machine. The memory type, and the speed it will actually run at, come from the processor in it. That is why RAMindex also describes 113processor families, 80 Intel and 33 AMD, and lets you start from either the machine or the processor. Processors are researched the same way as machines, from the vendor's own documentation, under the same rule: a figure established only once is not published.

This matters most where buyers are most often caught out. A server rated for 6400 MT/s memory usually reaches 6400 only with one module per channel. Fill the second slot on every channel and the same machine runs the same memory slower: 5200 on current Intel platforms, 4400 on several single-socket AMD ones. Wherever a vendor states both speeds, both are published, because the faster one on its own is a promise the machine stops keeping once it is full.

Some vendors print a single “up to” speed that is really the rating of the module rather than the speed of the machine. In that case the machine's figure is the one recorded.

Current server memory adds one more complication: MRDIMM, a DDR5 type that reaches higher bandwidth than a registered module but is supported only one per channel and only by some processors. A machine that takes both types is listed as taking both, each with its own ceiling, because they are genuinely different purchases. On one current server, registered memory reaches 8TB while MRDIMM reaches 1TB at a considerably higher speed.

What RAMindex does not claim

• No ratings or reviews. RAMindex sells nothing and has no customers to rate anything.
• No stock or delivery promises. Availability belongs to the seller and to eBay.
• No compatibility claim without a source, and no figure a vendor did not publish. A machine's maximum is never worked out by multiplying its slot count by its largest module, because vendors routinely cap the total below what the slots would hold.

Commission does not change the order

Links to eBay listings are affiliate links: RAMindex earns a commission on qualifying purchases, at no extra cost to you. The commission does not change which listings appear or the order they appear in. The order is price per gigabyte, worked out the same way for every row, and there is no paid placement of any kind.