I’m often asked by clients to help them choose a PC to run Excel models, particularly large project finance models that might take several minutes to solve with a macro. Here’s my advice:
Laptop or desktop - almost all of my clients want a laptop, so this piece just looks at laptop options, but as a rough rule of thumb, with a desktop you get about twice the power for half the price, so if you want a really fast PC for Excel, you should consider a separate desktop PC.
CPU - for the actual calculation of a model, this is by far the most important factor, but don’t get sucked in by the clock speed. Excel can use multi thread processing very well (for most tasks) and so a quad core i7 with a low clock speed will calculate much faster than a dual core i7 with a high clock speed, although the battery life will suffer. Look for QM, QE, XM, MQ, HQ or EQ in the name, these are all quad core CPUs. Avoid anything with a single letter, typically M or U, they’ll usually be significantly slower.
As an example, an i7-4558U has a clock speed of 2.8 GHz, but for Excel it will be much slower than an i7-4702HQ, with a clock speed of 2.2 GHz.
Memory - unless you’re using 64-bit Excel (and most people aren't), you’re not really going to notice any benefit from having more than 8Gb of RAM – even 4Gb is often enough, as 32-bit Excel has a limit of 2Gb. So no matter how much memory you have in your laptop, Excel will only be able to use 2Gb. However if you are using very large spreadsheets there are three ways to avoid this 2Gb limit:
- Use 64-bit Excel, which has no memory limit;
- Open each spreadsheet in a separate instance of Excel (press Alt when opening Excel); or
- Hack your excel.exe file to increase its memory limit from 2Gb to 4Gb. This is easy to do but beyond the scope of this article, contact me if you want to know how.
Keyboard layout - when I look at a new laptop the first thing I check is the position of the Home, End, PgUp/PgDn, arrow and Ctrl/Shift keys. If they don’t feel comfortable then you’re going to hate using the laptop’s keyboard for Excel.
Also, any laptop that combines the F1-F12 keys with Home, End, PgUp/PgDn is a complete non-starter for Excel. Yes Microsoft, that includes the otherwise-perfect Surface Pro 3/4/Book.
Screen size - although most laptops are usually plugged into a large screen on a desk, there are of course times when you’ll use it away from your desk. If you use it a lot on the road then go for the biggest screen you can. Sure it’ll be heavier, but when you’re stuck in a hotel room at 3am trying to finish your model before the investor meeting 6 hours later, you’ll be glad you’ve got a big screen.
Touch screen? - touch screens (on PCs) are one of those innovations that you think are gimmicky when you first get one. Then after a month using it you pick up a non-touch screen and you get really frustrated when touching the screen does nothing. Ok, so I really only touch the screen for web browsing and reading documents as in Excel I find it’s simply quicker and easier to use the keyboard or mouse – but who uses a laptop just for Excel?
SDD or HDD - when Excel opens a file it reads the whole file into RAM, so once it’s open you won’t notice any speed difference between an SSD and HDD. But in every other way an SSD is vastly superior and once you’ve used one you’ll never go back to a HDD. In fact, given the failure rate of HDDs, I’m always surprised to still see them used in corporate laptops. To compound the risk of drive failure, their higher capacity just encourages users to store all their data on their C drive rather than the network or cloud.
WiFi - these days WiFi is the first layer in Maslow’s hierarchy of needs and even in corporate offices, many laptops connect to the network over WiFi rather than via an Ethernet cable. Unfortunately, some new laptops still ship with the slower N WiFi. AC WiFi is significantly faster and is becoming more common, definitely get it if you can.
GPU - higher end laptops will often have a dedicated graphics chip – look for an Nvidia or Radeon sticker on the case. However, unlike games, Excel doesn’t really benefit from a separate graphics card, so unless budget isn’t an issue or you like playing games in your downtime, don’t bother with one.
So in summary, if speed is your main priority, and you can't justify a desktop, pick the fastest quad core i7 chip you can afford, and after that choose the laptop based on how it physically feels to use.