Back in 2011 the Dell XPS 15 L502x offered a lot of goods considering its price. The build quality was very good and it also looked quite appealing given its competitors at that time. On the performance side there we’re a lot of options to customize the XPS up to your needs, including GeForce MX, 8GB RAM, a SSD, i7, …

I started with a more budget friendly configuration including a traditional HDD, Intel i5-2410M, 4GB RAM and Windows 7. Over the years my demand for higher performance hardware has lead me to replace the HDD with a SDD, and upgrade the RAM to 8Gb. I’ve also dropped Windows entirely in favor of Ubuntu.

I’ve now come to a point where i’m doing most of my work in Linux and so the current hardware is still decent enough to pull it all together. Though once in a while you bump into software that is only supported on Windows / MacOs and so like many of you there is a need for running software in some sort of virtual machine. For me that is VirtualBox, it’s not perfect but frankly I don’t need it all that often so I can perfectly live with it.

Since Windows10 is quite the memory hog I found that running it inside a VM would sometimes put me in the situation where I’m running out of RAM. As a result paging would kick in and performance would drop tremendously. As a quick and relatively cheap fix (at least compared buying a new machine) I decided to upgrade my RAM to 16Gb since decent kits can be found for roughly €80.

What I had:
4Gb Adata RAM 1333MHz + 4Gb Corsair ValueSelect RAM 1066MHz

What I’ve upgraded to:
2 x 8Gb Corsair Vengeance RAM 1600MHz

Note that officially this configuration is not supported by Dell because at the time this laptop was sold the 8Gb DRAM stick was non-existing.

Wether to check if the upgrade was worth the deal I ran I couple of tests using the Phoronix automated benchmark suite. Here are the results for running it native under Ubuntu 18.04 LTS:

We notice an overall system performance improvement from our RAM upgrade, though the difference is in most occasions rather small given that we’re never utilizing more than 8Gb of memory. The only performance increase can come from the lower latency RAM. Regarding the negative results in Gimp, I bet that’s an anomaly in my tests so take that results with a grain of salt.

More interestingly is to see what happens inside the VM since this is where we may run into problems. After the upgrade I was able to higher the virtual DRAM size from 5Gb to 8Gb. Note that the Intel HD3000 is used as GPU. It also uses the system DRAM which make it compete with the CPU for memory access. I also suggest not to compare these results with running them under Linux native since the Windows 10VM is running on a HDD instead. Here are the results when running the benchmark inside Windows 10 virtual machine hosted by Ubuntu 18.04LTS:

We can clearly see a bigger improvement here as expected. The main point of the article is that now our Windows 10 VM can take up to 8Gb RAM which at least gives us enough headroom to run some memory exhaustive applications.