Azure BLOB storage - Pricing and speed "Within the data center"

Question

I am quite sure I know the answer, just want to make sure I got this right.
From Azure In Action :

If I use the CloudBlobClient from a WCF service that sits in my WebRole, to access blobs (read/write/update) , so :

1) Does read/write/update charge as transaction or are they free ?

2) Does the speed of accessing those blobs is fast as mentioned in the note ?

Answer 1

If I use the CloudBlobClient from a WCF service that sits in my WebRole, to access blobs (read/write/update) , so : 1) Does read/write/update charge as transaction or are they free ?

Transaction metering is independent of where the requests are made from. Storage read/write/update is done via REST API calls (or through an SDK call that wraps the REST API calls). Each successful REST API call will effectively count as a transaction. Specific details of what constitutes a transaction (as well as what's NOT counted as a transaction) may be found here.

By accessing blob storage from your Worker / Web role, you'll avoid Internet-based speed issues, and you won't pay for any data egress. (Note: Data ingress to the data center is free).

2) Does the speed of accessing those blobs is fast as mentioned in the note ?

Speed between your role instance and storage is governed by two things:

1. Network bandwidth. The DS and GS series have documented network bandwidth. The other sizes only advertise IOPS rates for attached disks.
2. Transaction rate. On a given storage account, there are very specific documented performance targets. This article breaks down the numbers in detail for a storage account itself, as well as targets for blobs, tables and queues.