Will adding more RAM increase your SSD's performance?
22nd Dec 2013 | 11:00
We test to see how much of an impact more memory has on an SSD
More RAM is a perpetually tempting prospect. It's one of the cheapest upgrades you can buy for your system, and (in spite of what the man in PC World will tell you) the easiest to install.
The benefits of going beyond 4GB of memory have thus far remained nebulous. A system packed to the rafters with RAM isn't going to yield higher frame rates than a skinny 2GB machine, nor is it going to feel zippier when running a single application at a time.
Traditionally, the view has been that more memory is only useful if you switch between several demanding apps regularly, or insist on opening eight browser windows, each streaming a different exciting episode of Deep Space Nine at 1080p because, you know, technology.
More RAM, sir?
Now that SSDs are fairly commonplace in everything from weekend warrior laptops to water-cooled overclockers, there might be completely new benefits to running a RAM-heavy rig. Does having enough memory let you turn off the Windows Page File and save your SSD from unnecessary writes without risking system wobbliness?
Performance degradation over time can be a real issue for solid state drives, so the potential benefit's considerable. Then there's the idea of using the RAM your system isn't using at its peak memory usage (which will be quite a lot in an 8GB system) and turning it into a virtual RAM drive to be used as a scratch drive. Low latency gaming modules will not only deliver some lightning reads and writes, they could also take the load off your SSD in instances such as image or video editing when your editing software's constantly caching your steady progress.
But how tangible is that gain when you're working, and is it worth the risk of running out of available memory? Windows doesn't hang around to tell you what went wrong at that point - it's outta here. So say bye bye to any unsaved progress.
Join us as we contend with the many pitfalls of page files and ruminate the reads and writes of our beloved RAM drives, finding new and intricate ways to boost and reinvigorate your SSD, so you don't have to.
Performance degradation is a sad thing. When this tester first got his 256 GB Samsung SSD 830 over a year ago, it had stop-and-stare IOPS. Out of the box its incompressible reads/writes were around 500 MB/s to 400 MB/s, but after a year of heavy usage as a primary boot drive, you can go ahead and whack 100 MB/s of each of those figures. Ouch.
There's a metric tonne of information out there in the internet wilds regarding proper maintenance and performance tweaking for your solid state storage, and one increasingly popular hypothesis is that you may be able to harness surplus RAM and send it to your SSD's aid. With 8 GB of G.Skill Ares 1600MHz DDR3 memory sitting beneath our chassis and a 64-bit Windows install so every GB of those modules could be put to use, we thought we'd test the theory.
Our first port of call is the page file. When you're running low on physical memory on account of those eight Deep Space Nine HD streams running in unison, Windows starts moving your most infrequently accessed memory pages onto the root directory of your hard drive, freeing up any physical memory space. When that drive happens to be an SSD, that means Windows is performing a lot of writes, which degrades flash memory over time. Logic would seem to dictate that if you have enough memory in place, Windows doesn't need to reallocate resources away from it and you can save your SSD the stress by disabling the page file.
To do so, head to the Control Panel, then select 'System > Advanced System Settings > Advanced' and hit the 'Settings' button in Performance. Find the Advanced tab on that window, and click 'Change' in the Performance area. Now select your drive and choose 'No paging file.' You'll need to restart to put it in effect.
We're not talking about a performance tweak - doing away with paging isn't going to improve your synthetic benchmark scores. To prove it, we ran our beleaguered Samsung drive through AS SSD and ATTO benchmarks to find out its sequential read/write times for both incompressible and compressible data. Predictably, there was no real gain or loss of yardage in the performance stakes. What we did find though was a marked improvement in system agility when running our own, home made benchmark.
To simulate an everyday high-stress scenario, we ran (you guessed it) eight browser windows streaming HD video while at the same time simulating one week of Football Manager 13, switching back and forth between Chrome and the game and each minute to force our system into accessing memory pages for both applications. The results were encouraging: it took over a minute less to complete the FM week (which involved demoralising home defeats to both Everton and QPR both times, since you ask) with the page file disabled. That's because our memory's read/write speeds are off the scale compared to even an SSD, so by forcing the RAM to do the legwork we're also increasing performance.
You can smell the caveat coming, can't you? Here's the thing: this is the only scenario in which you'll see a benefit from disabling the page file. Sure, the modern age is playing hell with our attention spans and everything, but if you can't keep focused on one application for a minute without compulsively hitting [Alt]+[Tab] to reach the next, you're doomed never to enjoy anything ever again.
The point is, a performance gain in this one specific event - switching from one app to another - doesn't justify turning off the page file. Why? Because there's a good chance you're making your OS a whole lot wobblier by doing so. In the event you actually do run out of physical memory with no page file to fall back on, Windows is checking out of there with nary a thought for your unsaved files. We experienced that first hand during our Football Manager stress test.
The ram reality
You see, by using so much RAM on open applications, it can't be put to use on file caching or handy tech like SuperFetch that keeps commonly used files close at hand by pre-loading them. In short - there is a performance gain involved in disabling the page file and forcing your physical memory to hold all page data, but it's wrapped in barbed wire.
Our Samsung SSD 830's none the nippier for dabbling with page file settings, and although in theory we might increase its lifespan by turning it off the side effects aren't encouraging. But there's one more avenue to explore: turning the GBs of RAM you're not using into a scratch device. The idea here is to create somewhere else for thrashing-heavy applications. And what better place to do it than on a virtual disk in your RAM?
We've already mentioned those impossibly quick IOPS compared to either solid state or mechanical storage. First off you need to establish how much memory you can actually assign to a virtual disk. Do this by running a resource-hogging game and another program like iTunes, then check out the Performance tab in Task Manager.
We used RAMDisk to create the drive. It allows partitions of up to 8GB for free, and it's simple. Use it to create a FAT32 drive, then add it as a volume in Disk Management (search for it in the Start menu).
Once Windows finds it, you need to tell it where to cache temporary files. Do this in Control Panel by clicking 'System > Advanced System Settings > Advanced', then hit the 'Environmental Variables' button and select your new virtual scratch device.
After a few teething problems allocating just the right amount of RAM to maintain system stability, we're onto something. Our SSD's performance remains the same in synthetic benchmarks, but thanks to the scratch device it'll live longer: each multi-level cell (MLC) in a flash memory device cell is given 10,000 erase/write cycle lifespan before it fails. So, by diverting these to a RAM scratch disk we're increasing SSD longevity.
So when it comes to the world of solid state drives, the more memory you have, the better. Our paging experiment shows it doesn't pay to turn it off, but the fact remains that the more system memory is available, the less your system needs to write to the page file. In systems above 8 GB, you could easily partition 2-4 GB off for use as a virtual scratch device, while also keeping enough memory available to minimise paging.
We put a one-year-old 256 GB samsung SSD 830 through the AS SSD and ATTO benchmarks to determine its sequential read/writer speeds, and stress-tested our system by running Football Manager 2013 and eight tabs running 1080p video in Chrome simultaneously. The idea isn't to look for performance gains, but to determine stability and look for anomalies as we alter system settings.
Football Manager 2013: Time in seconds: Faster is better
NO PAGE FILE: 4:11
2GB RAM DISK: 4:39
Sequential read performance (incompressible)
AS SSD: Megabytes per second: Hiigher is better
NO PAGE FILE: 266
2GB RAM DISK: 296
Sequential write performance (incompressible)
AS SSD: Megabytes per second:Higher is better
NO PAGE FILE: 166
2GB RAM DISK: 164
Sequential read performance (compressible)
ATTO SSD: Megabytes per second: Higher is better
NO PAGE FILE: 298
2GB RAM DISK: 289
Sequential write performance (compressible)
ATTO SSD Megabytes per second: Higher is better
NO PAGE FILE: 172
2GB RAM DISK: 172