All DDR Is The Same
In Part 1, we examined some basic facts about DRAM. Now, we’ll look at some topics that are often more contentious. Here's what we’ll cover in Part 2:
- All DDR3 Is The Same
- Just Add More DRAM
- There Are Only A Few DIMM Manufacturers
- 3200 MT/s Support Means You Can Use Any DRAM
- Mixed DRAM Runs At The Speed (Or Timings) Of The Slowest DIMM
- It’s Cheaper To Buy Two Sets Of DIMMs Than Larger, More Expensive Sets
- DRAM Will Run Faster With All Slots Filled
- There Are No Performance Gains With DRAM Faster Than 1600 MT/s
- 8GB Is All You'll Need For The Next X Years
- You’ll Never Use Or Need 16GB Or More
- I’m Not Using All My DRAM, So More DRAM Won’t Increase Speed
- A 64-bit OS Lets You Run All The DRAM You Want
- 1.65 Volt DRAM Will Damage Your Intel CPU
- Dual-Channel Mode Doubles The Data Rate, Or Is Twice As Fast
All DDR3 Is The Same
This topic alone could take up a lot of space, but I will try to keep it short and offer some suggestions. Here are a few examples:
- I’ve mentioned Kingston’s line of Fury DRAM, which doesn't come with an XMP profile but instead operates using plug and play. They look nice, come in a variety of heat sink colors, are reasonably priced and appeal to people with older systems who want to upgrade their DRAM. But since they are based off PnP, they will operate only under various motherboard chipsets: H67, P67, Z68, Z77, Z87 and H61 from Intel, along with AMD's A75, A87, A88, A89, A78 and E35. You can include Z87 and Z97. The sets I listed are direct from the company’s product page.
- The actual chips also differ:Most of the DRAM being manufactured today uses high-density, 4Gb memory chips, whereas older DDR3 used lower-density 2Gb chips. Older memory controllers are often limited to lower densities. One of our editors recently found that none of his P55 motherboards worked with any of his 8GB modules, and if modules with different densities are mixed, a module can become undetected or unstable.There is a number of different companies that make memory chips, and they make them to their own specifications. They also make multiple models of each chip. Each of those lines is split up or binned according to the strength of the chip.
- Most enthusiast-oriented motherboards are designed to take non-error-correcting coding (ECC), unbuffered DRAM. Usually, ECC is for servers and professional workstations where data integrity is critical, and buffered (registered) DIMMs are used exclusively in servers that require ultra-high memory capacity. Sharing technology among high-end platforms allows some enthusiasts to have the option of using ECC on their motherboards.
- There are other examples covered elsewhere, like DRAM with a data rate that’s too high for your CPU (but still functions at a slower default data rate).
Usually, I suggest checking with the DRAM manufacturers, which spend a lot of time testing their memory on the various motherboards out there. The motherboard manufacturers provide a qualified vendors list (QVL) of the DRAM they have tested with a given product, but it usually consists only of the small variety of DRAM they have available in their labs and isn’t as reliable as checking directly with the DRAM manufacturers. In the Tom's Hardware forums, I have found many rather knowledgeable members who provide good advice on various DRAM for specific motherboards and platforms, as well as information about what data rates the different CPUs can handle.