Computer Architecture on Circuit Quest

DDR vs GDDR vs HBM: How GPU Memory (VRAM) Actually Works

Sun, 06 Sep 2026 00:00:00 +0000

In the memory map article, I told you VRAM is just DRAM that belongs to the GPU. True, but it skips the actually interesting question: DRAM, sure, but which DRAM, and why can’t a graphics card just use the same DDR sticks your motherboard uses?

The DDR article showed you that DDR, DDR2, all the way through DDR5, are one lineage built to solve one problem: answer a CPU core fast, one request at a time. A GPU has a completely different problem. So it grew two completely different memory families out of that same DDR foundation — GDDR and HBM. Let’s see why.

SRAM vs DRAM vs SDRAM: The Cell-Level Differences (and Where DDR Fits In)

Sun, 06 Sep 2026 00:00:00 +0000

In the memory map article, I told you that SRAM and DRAM are the two basic cell designs everything else descends from, and that SDRAM and DDR are just generations of the DRAM family, not separate technologies. That’s a big claim, so let’s prove it properly this time.

Here’s the question we’re going to answer: when you see “DDR5 SDRAM” printed on a memory stick, is that just marketing repeating itself, or are DDR and SDRAM genuinely two different things bolted together? By the end of this article you’ll be able to answer that yourself, because we’re going to open the hood and look at the actual transistors and the actual clock edges.

Types of Computer Memory: What are DDR, VRAM, HBM, Cache, EEPROM, and others?

Sun, 30 Aug 2026 00:00:00 +0000

If you’ve ever tried to buy a new laptop, build a PC, or even read about the latest AI chips in the news, you’ve probably run into a complete alphabet soup. One ad boasts DDR5 and an NVMe SSD, a graphics card review goes on about GDDR7 VRAM, and an AI chip uses HBM4. To make it worse, if you play with Arduinos like I do, you get hit with Flash, SRAM, and EEPROM on a single board.