The ship was armed with a main battery of twelve 10.5 cm SK L/45 guns and had a top speed of 27.5 knots (50.9 km/h; 31.6 mph).

Magdeburg was used as a torpedo test ship after her commissioning until the outbreak of World War I in August 1914, when she was brought to active service and deployed to the Baltic.

On the 26th, she participated in a sweep of the entrance to the Gulf of Finland; while steaming off the Estonian coast, she ran aground off the island of Odensholm and could not be freed.

These were powered by sixteen coal-fired Marine-type water-tube boilers, although they were later altered to use fuel oil that was sprayed on the coal to increase its burn rate.

After completing fitting-out work, she began a short period of builder's trials on 12 August 1912 before being commissioned into the High Seas Fleet eight days later, under the command of Fregattenkapitän (FK—Frigate Captain) Heinrich Rohardt.

[6][7] After completing her initial sea trials, Magdeburg was used as a torpedo test ship on 1 December, replacing the light cruiser Augsburg in that role.

She resumed torpedo test duties on 26 October, but again joined the fleet for exercises in the Kattegat later that year, after which she went on another training cruise in the Baltic in December.

As Europe drifted toward war during the July Crisis, Magdeburg was ordered to patrol the Bay of Kiel to help secure the port's defenses.

[8] Following the outbreak of World War I at the end of July, she was assigned to the Coastal Defense Division in the Baltic Sea, under the command of Rear Admiral Robert Mischke.

She then joined the rest of the Coastal Defense Division, which was sent north to attack Russian positions in Finland that lasted from 9 to 15 August.

[8][9] On 17 August, Magdeburg, Augsburg, and three torpedo boats, sortied to escort the minelayer Deutschland, and the next day, they encountered a pair of powerful Russian armored cruisers, Admiral Makarov and Gromoboi.

The Russian commander, under the mistaken assumption that the German armored cruisers Roon and Prinz Heinrich were present, did not attack and both forces and withdrew.

Prince Heinrich, the overall commander of the Baltic naval forces, replaced Mischke with Konteradmiral (Rear Admiral) Ehler Behring.

Behring ordered the operation for 26 August to sweep for Russian reconnaissance forces in the entrance to the Gulf of Finland; Magdeburg was also to bombard the signal station at Odensholm on the Estonian coast.

She encountered heavy fog in the early hours of 26 August while steaming at a speed of 15 knots (28 km/h; 17 mph), and at 01:13, she ran aground near the lighthouse at Odensholm.

[11] While the evacuation was going on, the Russian cruisers Bogatyr and Pallada appeared at around 09:00, having been alerted to the situation by the signal station that Magdeburg had been unable to destroy.

With the code books and cipher key, the British were able to track the movements of most German warships; this information could be passed on to the Admiral John Jellicoe, the commander of the Grand Fleet.

This allowed the British to ambush parts of or the entire German fleet on several occasions, most successfully at the Battles of Dogger Bank in January 1915 and Jutland in May 1916.