Computers
Computers
Main Page
Automobiles
Computers
Paintball
I'm often asked many of the same questions, by countless people across various community sites and forums, about the various aspects on a great many topics... some very simply stated questions, like "how does whatever work" with some very long and drawn out answers. This is my attempt to consolidate my numerous posts into a single location that I can easily manage and simply direct people to (hopefully saving me time in retyping the same answers over and over again. This is not meant to be an exhaustive listing, but rather an ever-growing culmunation of knowledge and experience. As such, I've opened the entire section of 'Everything About' for all 'Super Users' to freely add and modify!!!
Virtualization
Benefits
Consolidation is only one aspect of virtualizing PC's, there's a good many other benefits from having this abstraction layer (such as security, redundancy, portability, electric bills, licensing, etc)
Microsoft vs VMware
Microsoft has historically not paid much development resources to virtualization, but that's not necessarily to say they're behind the curve either (even though they are at the moment). They did what all big companies do, buy the technology... Virtual PC 2004 is actually Connectix Virtual Server made free after the aquisition. Virtual PC 2007 only solidified and expanded it's current ability. Windows Server 2008 has virtualization built in... and attempts to leapfrog back into the competitive fray (overnight as it were). The market implications alone of having this ability in every Windows server is compelling.
VMware for Dummies:
Server = Can create & run virtual machines
Player = Can only run virtual machines, not create
Storage
A virtual disk is simply a file (e.g. test_box.vmdk) you can store on any medium (local drive, network drive, removable drive). It would be the equivalent of zip'ing up your entire hard drive into a single file. With virtual drives, you can either a.) have them grown & shrink as you create & delete files on the virtual disk, or b.) allocate an entire amount from the get-go. For reasons I won't go into, you should almost always use the grow/shrink method. Benefits of a virtual disk include being able to literally copy the virtual machine (vm) to another computer, and launching the virtual machine on completely different hardware... all without the vm knowing. Also, where storage space is a limitation, it's also a better consolidation.
Memory
Performance: General Rules of Thumb
1.) Duplicate sticks of memory regardless of capacity will always yield ~5% better performance (with motherboards supporting Dual Channel) i.e. 2x512MB is ~5% faster than 1x1GB. Don't make a mistake by putting in an odd number of memory sticks, by doing so you're disabling the dual channel capabilities. Stick to a single pair of memory if at all possible, the 2nd pair adds addressing overheads.
2.) All motherboard chipsets are only capable of adressing a certain amount of memory before the point of diminishing returns is met with regard to degrading performance (ie. there's a technical limit on capacity, as well as recommended limit - before performance degrades).
3.) Differing ratings in sticks of memory will only operate at the lowest common denominator... or there WILL be stability concerns. Running DDR333 w/ another DDR500 @ DDR500 speeds is a substantial overclock for DDR333. The same is true w/ CAS (latency). Running CAS4 with CAS2 is more than a substantial overclock for CAS4.
4.) Synchronous bus is VERY nice, but not nearly as much these days since newer chipsets do seperate the 2x better (which is very good).
VERY Generally speaking, recommended limits for various generations are:
486D4/Pentium 1/Cyrix/AMDK6 = 64MB
Pentium 2/AMDK6-2/AMDK6-3 = 128MB
Pentium 3/AMDK8 Thunderbird's = 256MB
Pentium 4/AMDK8 XP's = 1GB
Pentium D/AMD64/X2 = 2GB
Core Duo/Opteron/Xeon = 4GB+
Itanium = XTB
There are obvious differences in chipsets as it pertains to quality & capability. Therefore, if you buy a brand-x value brand motherboard for ~$5 and have a ~PD/A64/X2... you can expect a good performance hit w/ 2GB, so stick w/ 1GB. Also important to note, many 1st-round Core Duo motherboards are only capable of 2GB with all recent worthwhile boards supporting 4GB.
Performance: Ratings
Connectivity
Cable vs DSL
Historically, DSL has always had lower latency than Cable; Cable has always had more throughput than DSL. Now there's a new player: FIOS (fiber to the home), think 20+Mbps easy. DSL and Cable should both scale that high with time. I believe there are already a couple test markets with ~12Mbps Cable.
These days w/ latency all pretty well standardized, your decision is clearly based on pricing and availability in your local market: FIOS (~10-20Mbps) > Cable (~6-8Mbps) > aDSL (~1.5-6Mbps)
Synchronous Connections and Poor Marketing
Primary reasons for synchronous connections include (but are not limited to) VoIP, servers, and VPN connections for both remote users and offices. sDSL, sometimes wrongly marketed, is actually iDSL... which, ironically, isn't *really* even DSL at all. It's ISDN. Add to this complexity, what a provider might call an 'unprovisioned' T-circuit isn't actually a T-circuit. Often times (due to stiff competition), it's simply one or more DSL lines multiplexed (strung together).