L1 is SRAM/L2 is DRAM Caches are on the same die (physically) as the processor, to put it simply: they are insta-memory on hand - there is no intermediary between the CPU and the cache (traditional memory has to go through buses). It goes without saying that 'the bigger the better' The cache is a pre-fetch area, it improves all software speed, it's not the same as a 20% increase though - to give a simply analogy: In an office you are the CPU and you're signing papers (executing instructions). Your filing assistant is your memory - you can have a potentially better/faster assistant by paying more (so she walks faster). Your cache is your desk space, you will normally always sign papers that you can reach by hand, and your assistant takes the signed papers and stores them away and brings new papers. Remember that your CPU is rarely at 100% (not even during trading). If your desk always has paper nearby, then what matters is how fast you work, and it matters less that your assistant isn't running With a bigger cache, it provides a gap before it makes a difference, I hope I've explained it thoroughly L1 SRAM is faster than L2 DRAM is faster than L3 (shared cache) is faster than DDR
^^ Good explanation! Think of it this way. It seems small that it's only 12mb but it's physically within the CPU. It's like the difference between being thirsty and having a full glass of water in your hand - or having to go to the sink and get a refill before you can drink. Your Front-Side-Bus (FSB) is what connects your memory (RAM) to your CPU. FSB has speeds like CPUs have clock speeds where different motherboards can be faster or slower. It is exactly like the difference between having a file sitting on your hard drive vs. already open and residing in your computer's system RAM - you can access both easily and quickly however if it was already open it is at your fingertips. This is another reason why I like building dual-CPU (two Intel Xeon CPUs) machines for traders vs. a single quad-core. For $500-$600 you can get a really kick-ass dual-CPU machine that has about the same amount of cache as an i7 usually with a faster clock speed. (Yes there are differences between FSB speeds + ddr2 vs. ddr3 but there is also a big difference between 2.4ghz and 3.2-3.4ghz clock speed.) You can quite often combine two high-end (but older) CPUs to equally perform or outperform a modern CPU for much less cost.
Many thanks for your detailed and enlightening feedback, MyTotoro and WinstonTJ. It's good to have neighbors like you guys on ET.
People never mention this but SSDs provide a significant power saving advantage over traditional hard drives, so if you care about your carbon footprint, then it has to be SSD.
SOME SSDs have a power savings advantage...but a lot of cheap SSDs will draw just as much if not more power. Check power specifications if this is something you care about or if you're going to drop an SSD into a laptop.
A fanless graphics card is a good tip. My machine makes too much noise. This will definitely be part of my next upgrade.
Good point, a lot of the SSD's are theoretically better - hence marginally in real-world applications, I'm a heavy user of Adobe products and it makes some difference, I don't do video work much, but I suppose once I start backtesting I'll want to opt for a SSD. (But honestly, couldn't you just flick on the simulation when you head for sleep, tell your computer to go to sleep in 1-2 hours, whatever you feel is necessary and come back in the morning to have results? - I'm a university student and I have short bursts of access, so this backtesting strategy with a $50 hard drive makes more sense than dropping $200 - I do have a Crucial C300 on my computer and it's nice but not a pre-requisite). For those of you who have more hardware experience with building computers can consider submerged pc's - from mineral oil, etc - and for the even more DIY ones - you can make even better/funkier solutions Someone should write a full blown guide on and get it stickied When to upgrade What to upgrade to Minimum rig Nice to have rig I-have-money rig I NEED the i7 Extremes. Possible modifications
Discretionary trading using the 2011 mid Mac mini (2.5 Ghz i5-2520M), 8 Gb RAM and 128 GB SSD running windows 7. althought the machine at stock standard fan speeds runs too hot for my liking with a small program I've increased the minimum speed to the same speed as the fan has in the mac mini server and all is well. CPU power is not the issue, biggest issue I've found was the speed data went in and out of the CPU so Sandy bridge made a noticeable difference. Above all this is the quietest machine I've owned and it can drive three monitors (the other models of the 2011 mac minis can only drive two monitors) Am using a Dell U2410M monitor and do no longer have the "need" for two or three. When travelling I rely on the hotel TV to have either DVI or HTMI so carry the Mac mini in hand luggage (1.1 Kg) and the keyboard/mouse in checked in luggage. (eyes are not very good any longer so no more laptops)