not an answer to your question but something to think about
remember that whatever feed you use you are always at the mercy of the internet and the more jumps your data makes the longer it takes to reach you.
You may live In London and be getting FTSE data from a provider who buys it from a provider who takes it from LSE. The first level provider may be in USA, the second level provider may be in London. However when you logged on the connection you got today to your London provider was London/Germany Tokyo/New York/London.Tomorrow you may get London /NY/London/Paris/London/London.
That takes care of the physical distance issues but still leaves switching and bandwidth availability to slow things down along with processing compression algorithms and transfer into an image on your screen.
Remember also that your trading platform speed is a totally different issue
There are also your ISP speed/connection questions to consider
Some of these things you have control over - over most you have none whatever. We should be talking of fractions of a second here but regrettably this is not always the case.
I am not trying to provide an answer here - just musing on the difficulties we face in the quest for fast data provision and execution
Updata now use a Comstock feed and regrettably there are still occassions where users have demonstrated delays of up to a minute. However I am sure that this is something that could be said selectively of all feeds depending on the conditions
As Paul says satellite is a slow method - especially if you are using it for the return (place order) journey too.
The fastest datafeed is of course if you are sitting in the Exchange. looking at the market data system (who aren't actually allowed to trade ). preferably of course you are looking at the prices coming right off the trading host onto a gateway. depending on the precise exchange that you are trading on of couse, and the intermediate infrastructure/ third parties etc in between. generally though you are best off if you are sitting in a member office trading on an exchange gateway in the same financial center as the market you are trading on
Eurex - Frankfurt
London EASY network - Matif / Monep belgian futures LIFFE
CBOT - member office in NewYork failing that a Chicago member
LSE - London members
QV feeds will nearly always be slower than "Direct access" via the exchange
best datafeed=my desk
It has been my Job to investigate "slowdows" that traders and QuoteVendors Report and would like to reinforce to everyone that every system that the data interacts with on its way to you might add a certain amount of latency which will vary acording to the rules of that system. and I mean EVERY system from the CPU that the contract is traded on to the distribution/ Feed Handlers, Quotesystems, QV systems their global disribution their internet connection your internet connection, to the crap slow Java applet which most people seem to use to veiw price graphs. the data "probably" goes through at least 5 different computers before it even gets near a QV let alone the internet or your own desktop.
Its been my experience with IQFeed that their data makes 20 hops. What this means is that the data (and this is from IQFeeds servers in NY not from the US exchanges) to my desktop passes through 20 routers or segmented networks on the internet (I have broadband). Add the latency from the 20 segments not to mention data error correction and bandwidth peaks and the delay could be in the 10s of seconds if not minutes. Its not speed though thats the main issue (a second delay won't make much of a difference if trading from 5minute charts), it has to be quality. Although for speed and quality Direct Access from the exchange must be preferable.
One thing I know for sure - ALL prop houses in London use CQG - so it cant be that bad.
I agree 100% about the latency the internet introduces - but lets face it, most of that will be determined by the ISP you use rather than the data vendor itself. As dglynn pointed out, how important is it to have the fastest data feed? If you're scalping for ticks, the data feed is a big issue - you'd be unwise to sit at home with your broadband for such an operation. However trading a 5 min chart is a different kettle of fish.
Given these issues, I'd rather go for accuracy rather than speed, as any mili second improvement will be lost on the internet.
It appears to me that you are all concerned with the technicality of data rather than with the message that the data delivers.
dglynn is absolutely correct in what he explains. We had all this verified 4 months ago, but all these arguments are technical for the sake of technicality, although very interesting. The point I wish to make is that whilst everyone is nattering about the technical aspect of the datafeed, in terms of speed, no one seems to be concerned with what the data itself is showing.
What the datafeed is showing and what you all should be concentrating on is the sequence of pricing schedules, which are the clues as to which way the market is really heading, and on the ability to execute in a nanosecond a decision to buy or sell on the internet as a result of having developed instantaneous conditional reflex. This faculty is what everybody plays about with and no one attempts to perfect. Why ? It does not appear to be easy - but it is ! What you need to do is to develop the correct mindset and concentrate and what really matters, that is the ability to read the market, and to respond seamlessly. I recognise it takes between 4 to 6 years to develop this faculty also as a result of mindmapping the way the market really works, but just concentrating attention on what is mere detail does not lead to consistent success, which is and must be the ultimate object.
A further note:~ When you have mastered the above concepts, and you know you have mastered them because your results prove you have mastered them, then it does not matter if the datafeed is a bit slow or whatever, because you can make up for this because of your developed ability to anticipate moves, and /or their potential to really motor or not, therefore being able against the odds, to circumvent and overcome these obstacles and still succeed. But you have to work at it before it can work for you. You have to posess the right character. You have to be able to be totally adult. You have to be totally in charge of yourself and what you are in. This higher level of trading requires self government of the highest order. Not everybody can attain it, but everyone owes it to themselves to try.