SSD memory types
You often espouse the benefits Q of SSDS. However, when looking to buy one recently I found myself bamboozled by Amazon reviews saying things like: “Don’t buy this because it uses QLC chips. Go for the model with TLC chips instead!”. Could you shed light on the differences and whether they matter? I was hoping that using an SSD to replace the hard drive in my four-year-old laptop might speed things up, but all this stuff has put me off! James Day
A If you read our Cover Feature on SSDS in Issue 626, you’ll know that the main hurdle to buying and fitting an SSD is acquiring one with the correct physical interface for your computer. As that aspect is crucial, it was the focus of our feature.
However, as with almost any other area of technology, it’d be possible to drill down almost endlessly to consider the pros and cons of every component – including SSD memory chips.
The different types have their good and bad points, but it boils down to a mix of speed, reliability and cost. The C in TLC and QLC stands for ‘cell’. Each cell stores one, two, three or four bits of data, giving us singlelevel (SLC), multi-level (MLC), triple-level (TLC) and quad-level (QLC) cells. SSDS with TLC and QLC dominate the consumer market.
The higher ‘density’ of QLC chips makes QLC SSDS cheaper to produce, but fractionally reduces expected overall lifespan. This is because an individual cell’s resilience is degraded by an extremely tiny amount with each read or write operation. As each QLC holds more bits per cell, it will end up being read or written to more often than a TLC.
For most everyday users, we’d say don’t worry too much about any of this. Yes, QLC drives are theoretically less durable than TLC models, but in the real world both types will offer many years of reliable service.
Moreover, beyond the benchmark tests, few people would notice the speed differences between one SSD and another. But between a hard drive and SSD? The difference is stark – so don’t let the jargon put you off!
Want to know the difference between technical terms? Email noproblem@ computeractive.co.uk